block checking out fork pr for some events

Update changelog for v6.0.3 (#2446 )
Fix checkout init for SHA-256 repositories (#2439 )
2026-06-12 22:48:03 +00:00 · 2026-06-12 19:12:01 +00:00 · 2026-06-02 10:31:30 -04:00 · 2026-06-01 11:35:58 -04:00 · 2026-05-04 13:30:55 -04:00 · 2026-01-09 14:09:42 -06:00
31 changed files with 2501 additions and 297 deletions
@@ -22,7 +22,7 @@ jobs:
    runs-on: ubuntu-latest

    steps:
-      - uses: actions/checkout@v4.1.6
+      - uses: actions/checkout@v6

      - name: Set Node.js 24.x
        uses: actions/setup-node@v4
@@ -39,7 +39,7 @@ jobs:

    steps:
    - name: Checkout repository
-      uses: actions/checkout@v4.1.6
+      uses: actions/checkout@v6

    - name: Initialize CodeQL
      uses: github/codeql-action/init@v3
@@ -9,6 +9,6 @@ jobs:
    runs-on: ubuntu-latest
    name: Check licenses
    steps:
-      - uses: actions/checkout@v4.1.6
+      - uses: actions/checkout@v6
      - run: npm ci
      - run: npm run licensed-check
@@ -14,7 +14,7 @@ jobs:

    steps:
      - name: Checking out
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
      - name: Publish
        id: publish
        uses: actions/publish-immutable-action@0.0.3
@@ -19,7 +19,7 @@ jobs:
      - uses: actions/setup-node@v4
        with:
          node-version: 24.x
-      - uses: actions/checkout@v4.1.6
+      - uses: actions/checkout@v6
      - run: npm ci
      - run: npm run build
      - run: npm run format-check
@@ -37,7 +37,7 @@ jobs:
    steps:
      # Clone this repo
      - name: Checkout
-        uses: actions/checkout@v4.1.6
+        uses: actions/checkout@v6

      # Basic checkout
      - name: Checkout basic
@@ -87,6 +87,17 @@ jobs:
      - name: Verify fetch filter
        run: __test__/verify-fetch-filter.sh

+      # Fetch tags
+      - name: Checkout with fetch-tags
+        uses: ./
+        with:
+          ref: test-data/v2/basic
+          path: fetch-tags-test
+          fetch-tags: true
+      - name: Verify fetch-tags
+        shell: bash
+        run: __test__/verify-fetch-tags.sh
+
      # Sparse checkout
      - name: Sparse checkout
        uses: ./
@@ -165,6 +176,22 @@ jobs:
      - name: Verify submodules recursive
        run: __test__/verify-submodules-recursive.sh

+      # Worktree credentials
+      - name: Checkout for worktree test
+        uses: ./
+        with:
+          path: worktree-test
+      - name: Verify worktree credentials
+        shell: bash
+        run: __test__/verify-worktree.sh worktree-test worktree-branch
+
+      # Worktree credentials in container step
+      - name: Verify worktree credentials in container step
+        if: runner.os == 'Linux'
+        uses: docker://bitnami/git:latest
+        with:
+          args: bash __test__/verify-worktree.sh worktree-test container-worktree-branch
+
      # Basic checkout using REST API
      - name: Remove basic
        if: runner.os != 'windows'
@@ -202,7 +229,7 @@ jobs:
    steps:
      # Clone this repo
      - name: Checkout
-        uses: actions/checkout@v4.1.6
+        uses: actions/checkout@v6

      # Basic checkout using git
      - name: Checkout basic
@@ -234,7 +261,7 @@ jobs:
    steps:
      # Clone this repo
      - name: Checkout
-        uses: actions/checkout@v4.1.6
+        uses: actions/checkout@v6

      # Basic checkout using git
      - name: Checkout basic
@@ -264,7 +291,7 @@ jobs:
    steps:
      # Clone this repo
      - name: Checkout
-        uses: actions/checkout@v4.1.6
+        uses: actions/checkout@v6
        with:
          path: localClone

@@ -291,8 +318,8 @@ jobs:
          git fetch --no-tags --depth=1 origin +refs/heads/main:refs/remotes/origin/main

      # needed to make checkout post cleanup succeed
-      - name: Fix Checkout v4
-        uses: actions/checkout@v4.1.6
+      - name: Fix Checkout v6
+        uses: actions/checkout@v6
        with:
          path: localClone

@@ -301,13 +328,16 @@ jobs:
    steps:
      # Clone this repo
      - name: Checkout
-        uses: actions/checkout@v4.1.6
+        uses: actions/checkout@v6
+        with:
+          path: actions-checkout

      # Basic checkout using git
      - name: Checkout basic
        id: checkout
-        uses: ./
+        uses: ./actions-checkout
        with:
+          path: cloned-using-local-action
          ref: test-data/v2/basic

      # Verify output
@@ -325,7 +355,3 @@ jobs:
            echo "Expected commit to be 82f71901cf8c021332310dcc8cdba84c4193ff5d"
            exit 1
          fi
-
-      # needed to make checkout post cleanup succeed
-      - name: Fix Checkout
-        uses: actions/checkout@v4.1.6
@@ -23,7 +23,7 @@ jobs:
    # Note this update workflow can also be used as a rollback tool.
    # For that reason, it's best to pin `actions/checkout` to a known, stable version
    # (typically, about two releases back).
-    - uses: actions/checkout@v4.1.6
+    - uses: actions/checkout@v6
      with:
        fetch-depth: 0
    - name: Git config
@@ -26,7 +26,7 @@ jobs:
 
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6

      # Use `docker/login-action` to log in to GHCR.io. 
      # Once published, the packages are scoped to the account defined here.
@@ -1,10 +1,29 @@
 # Changelog

-## V5.0.0
+## v6.0.3
+* Fix checkout init for SHA-256 repositories by @yaananth in https://github.com/actions/checkout/pull/2439
+* fix: expand merge commit SHA regex and add SHA-256 test cases by @yaananth in https://github.com/actions/checkout/pull/2414
+
+## v6.0.2
+* Fix tag handling: preserve annotations and explicit fetch-tags by @ericsciple in https://github.com/actions/checkout/pull/2356
+
+## v6.0.1
+* Add worktree support for persist-credentials includeIf by @ericsciple in https://github.com/actions/checkout/pull/2327
+
+## v6.0.0
+* Persist creds to a separate file by @ericsciple in https://github.com/actions/checkout/pull/2286
+* Update README to include Node.js 24 support details and requirements by @salmanmkc in https://github.com/actions/checkout/pull/2248
+
+## v5.0.1
+* Port v6 cleanup to v5 by @ericsciple in https://github.com/actions/checkout/pull/2301
+
+## v5.0.0
 * Update actions checkout to use node 24 by @salmanmkc in https://github.com/actions/checkout/pull/2226

+## v4.3.1
+* Port v6 cleanup to v4 by @ericsciple in https://github.com/actions/checkout/pull/2305

-## V4.3.0
+## v4.3.0
 * docs: update README.md by @motss in https://github.com/actions/checkout/pull/1971
 * Add internal repos for checking out multiple repositories by @mouismail in https://github.com/actions/checkout/pull/1977
 * Documentation update - add recommended permissions to Readme by @benwells in https://github.com/actions/checkout/pull/2043
@@ -1,10 +1,22 @@
 [![Build and Test](https://github.com/actions/checkout/actions/workflows/test.yml/badge.svg)](https://github.com/actions/checkout/actions/workflows/test.yml)

-# Checkout V5
+# Checkout v6

-Checkout v5 now supports Node.js 24
+## What's new

-# Checkout V4
+- Improved credential security: `persist-credentials` now stores credentials in a separate file under `$RUNNER_TEMP` instead of directly in `.git/config`
+- No workflow changes required — `git fetch`, `git push`, etc. continue to work automatically
+- Running authenticated git commands from a [Docker container action](https://docs.github.com/actions/sharing-automations/creating-actions/creating-a-docker-container-action) requires Actions Runner [v2.329.0](https://github.com/actions/runner/releases/tag/v2.329.0) or later
+
+# Checkout v5
+
+## What's new
+
+- Updated to the node24 runtime
+  - This requires a minimum Actions Runner version of [v2.327.1](https://github.com/actions/runner/releases/tag/v2.327.1) to run.
+
+
+# Checkout v4

 This action checks-out your repository under `$GITHUB_WORKSPACE`, so your workflow can access it.

@@ -40,7 +52,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/

 <!-- start usage -->
 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    # Repository name with owner. For example, actions/checkout
    # Default: ${{ github.repository }}
@@ -148,15 +160,22 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
    # running from unless specified. Example URLs are https://github.com or
    # https://my-ghes-server.example.com
    github-server-url: ''
+
+    # Required to check out fork pull request code from a workflow triggered by
+    # `pull_request_target` or `workflow_run`. See [Pwn Requests](todo:need-link) for
+    # the risks. Set to `true` only after reviewing the risks.
+    # Default: false
+    allow-unsafe-pr-checkout: ''
 ```
 <!-- end usage -->

 # Scenarios

 - [Checkout V5](#checkout-v5)
+  - [What's new](#whats-new)
 - [Checkout V4](#checkout-v4)
    - [Note](#note)
- [What's new](#whats-new)
+- [What's new](#whats-new-1)
 - [Usage](#usage)
 - [Scenarios](#scenarios)
  - [Fetch only the root files](#fetch-only-the-root-files)
@@ -178,7 +197,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only the root files

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    sparse-checkout: .
 ```
@@ -186,7 +205,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only the root files and `.github` and `src` folder

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    sparse-checkout: |
      .github
@@ -196,7 +215,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch only a single file

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    sparse-checkout: |
      README.md
@@ -206,7 +225,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Fetch all history for all tags and branches

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    fetch-depth: 0
 ```
@@ -214,7 +233,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout a different branch

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    ref: my-branch
 ```
@@ -222,7 +241,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout HEAD^

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    fetch-depth: 2
 - run: git checkout HEAD^
@@ -232,12 +251,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/

 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6
  with:
    path: main

 - name: Checkout tools repo
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6
  with:
    repository: my-org/my-tools
    path: my-tools
@@ -248,10 +267,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/

 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6

 - name: Checkout tools repo
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6
  with:
    repository: my-org/my-tools
    path: my-tools
@@ -262,12 +281,12 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/

 ```yaml
 - name: Checkout
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6
  with:
    path: main

 - name: Checkout private tools
-  uses: actions/checkout@v5
+  uses: actions/checkout@v6
  with:
    repository: my-org/my-private-tools
    token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
@@ -280,7 +299,7 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
 ## Checkout pull request HEAD commit instead of merge commit

 ```yaml
- uses: actions/checkout@v5
+- uses: actions/checkout@v6
  with:
    ref: ${{ github.event.pull_request.head.sha }}
 ```
@@ -296,7 +315,7 @@ jobs:
  build:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 ```

 ## Push a commit using the built-in token
@@ -307,7 +326,7 @@ jobs:
  build:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - run: |
          date > generated.txt
          # Note: the following account information will not work on GHES
@@ -329,7 +348,7 @@ jobs:
  build:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
        with:
          ref: ${{ github.head_ref }}
      - run: |
@@ -86,16 +86,29 @@ describe('git-auth-helper tests', () => {
    // Act
    await authHelper.configureAuth()

-    // Assert config
-    const configContent = (
+    // Assert config - check that .git/config contains includeIf entries
+    const localConfigContent = (
      await fs.promises.readFile(localGitConfigPath)
    ).toString()
+    expect(
+      localConfigContent.indexOf('includeIf.gitdir:')
+    ).toBeGreaterThanOrEqual(0)
+
+    // Assert credentials config file contains the actual credentials
+    const credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBe(1)
+    const credentialsConfigPath = path.join(runnerTemp, credentialsFiles[0])
+    const credentialsContent = (
+      await fs.promises.readFile(credentialsConfigPath)
+    ).toString()
    const basicCredential = Buffer.from(
      `x-access-token:${settings.authToken}`,
      'utf8'
    ).toString('base64')
    expect(
-      configContent.indexOf(
+      credentialsContent.indexOf(
        `http.${expectedServerUrl}/.extraheader AUTHORIZATION: basic ${basicCredential}`
      )
    ).toBeGreaterThanOrEqual(0)
@@ -120,7 +133,7 @@ describe('git-auth-helper tests', () => {
    'inject https://github.com as github server url'
  it(configureAuth_AcceptsGitHubServerUrlSetToGHEC, async () => {
    await testAuthHeader(
-      configureAuth_AcceptsGitHubServerUrl,
+      configureAuth_AcceptsGitHubServerUrlSetToGHEC,
      'https://github.com'
    )
  })
@@ -141,12 +154,17 @@ describe('git-auth-helper tests', () => {
      // Act
      await authHelper.configureAuth()

-      // Assert config
-      const configContent = (
-        await fs.promises.readFile(localGitConfigPath)
+      // Assert config - check credentials config file (not local .git/config)
+      const credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+        f => f.startsWith('git-credentials-') && f.endsWith('.config')
+      )
+      expect(credentialsFiles.length).toBe(1)
+      const credentialsConfigPath = path.join(runnerTemp, credentialsFiles[0])
+      const credentialsContent = (
+        await fs.promises.readFile(credentialsConfigPath)
      ).toString()
      expect(
-        configContent.indexOf(
+        credentialsContent.indexOf(
          `http.https://github.com/.extraheader AUTHORIZATION`
        )
      ).toBeGreaterThanOrEqual(0)
@@ -251,13 +269,16 @@ describe('git-auth-helper tests', () => {
      expectedSshCommand
    )

-    // Asserty git config
+    // Assert git config
    const gitConfigLines = (await fs.promises.readFile(localGitConfigPath))
      .toString()
      .split('\n')
      .filter(x => x)
-    expect(gitConfigLines).toHaveLength(1)
-    expect(gitConfigLines[0]).toMatch(/^http\./)
+    // Should have includeIf entries pointing to credentials file
+    expect(gitConfigLines.length).toBeGreaterThan(0)
+    expect(
+      gitConfigLines.some(line => line.indexOf('includeIf.gitdir:') >= 0)
+    ).toBeTruthy()
  })

  const configureAuth_setsSshCommandWhenPersistCredentialsTrue =
@@ -419,8 +440,20 @@ describe('git-auth-helper tests', () => {
    expect(
      configContent.indexOf('value-from-global-config')
    ).toBeGreaterThanOrEqual(0)
+    // Global config should have include.path pointing to credentials file
+    expect(configContent.indexOf('include.path')).toBeGreaterThanOrEqual(0)
+
+    // Check credentials in the separate config file
+    const credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBeGreaterThan(0)
+    const credentialsConfigPath = path.join(runnerTemp, credentialsFiles[0])
+    const credentialsContent = (
+      await fs.promises.readFile(credentialsConfigPath)
+    ).toString()
    expect(
-      configContent.indexOf(
+      credentialsContent.indexOf(
        `http.https://github.com/.extraheader AUTHORIZATION: basic ${basicCredential}`
      )
    ).toBeGreaterThanOrEqual(0)
@@ -463,8 +496,20 @@ describe('git-auth-helper tests', () => {
      const configContent = (
        await fs.promises.readFile(path.join(git.env['HOME'], '.gitconfig'))
      ).toString()
+      // Global config should have include.path pointing to credentials file
+      expect(configContent.indexOf('include.path')).toBeGreaterThanOrEqual(0)
+
+      // Check credentials in the separate config file
+      const credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+        f => f.startsWith('git-credentials-') && f.endsWith('.config')
+      )
+      expect(credentialsFiles.length).toBeGreaterThan(0)
+      const credentialsConfigPath = path.join(runnerTemp, credentialsFiles[0])
+      const credentialsContent = (
+        await fs.promises.readFile(credentialsConfigPath)
+      ).toString()
      expect(
-        configContent.indexOf(
+        credentialsContent.indexOf(
          `http.https://github.com/.extraheader AUTHORIZATION: basic ${basicCredential}`
        )
      ).toBeGreaterThanOrEqual(0)
@@ -550,15 +595,15 @@ describe('git-auth-helper tests', () => {
      await authHelper.configureSubmoduleAuth()

      // Assert
-      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(4)
+      // Should configure insteadOf (2 calls for two values)
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(3)
      expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
        /unset-all.*insteadOf/
      )
-      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/http.*extraheader/)
-      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(
+      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(
        /url.*insteadOf.*git@github.com:/
      )
-      expect(mockSubmoduleForeach.mock.calls[3][0]).toMatch(
+      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(
        /url.*insteadOf.*org-123456@github.com:/
      )
    }
@@ -589,12 +634,12 @@ describe('git-auth-helper tests', () => {
      await authHelper.configureSubmoduleAuth()

      // Assert
-      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(3)
+      // Should configure sshCommand (1 call)
+      expect(mockSubmoduleForeach).toHaveBeenCalledTimes(2)
      expect(mockSubmoduleForeach.mock.calls[0][0]).toMatch(
        /unset-all.*insteadOf/
      )
-      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/http.*extraheader/)
-      expect(mockSubmoduleForeach.mock.calls[2][0]).toMatch(/core\.sshCommand/)
+      expect(mockSubmoduleForeach.mock.calls[1][0]).toMatch(/core\.sshCommand/)
    }
  )

@@ -660,19 +705,201 @@ describe('git-auth-helper tests', () => {
    await setup(removeAuth_removesToken)
    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
    await authHelper.configureAuth()
-    let gitConfigContent = (
+
+    // Verify includeIf entries exist in local config
+    let localConfigContent = (
      await fs.promises.readFile(localGitConfigPath)
    ).toString()
-    expect(gitConfigContent.indexOf('http.')).toBeGreaterThanOrEqual(0) // sanity check
+    expect(
+      localConfigContent.indexOf('includeIf.gitdir:')
+    ).toBeGreaterThanOrEqual(0)
+
+    // Verify both host and container includeIf entries are present
+    const hostGitDir = path.join(workspace, '.git').replace(/\\/g, '/')
+    expect(
+      localConfigContent.indexOf(`includeIf.gitdir:${hostGitDir}.path`)
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      localConfigContent.indexOf('includeIf.gitdir:/github/workspace/.git.path')
+    ).toBeGreaterThanOrEqual(0)
+
+    // Verify credentials file exists
+    let credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBe(1)
+    const credentialsFilePath = path.join(runnerTemp, credentialsFiles[0])
+
+    // Verify credentials file contains the auth token
+    let credentialsContent = (
+      await fs.promises.readFile(credentialsFilePath)
+    ).toString()
+    const basicCredential = Buffer.from(
+      `x-access-token:${settings.authToken}`,
+      'utf8'
+    ).toString('base64')
+    expect(
+      credentialsContent.indexOf(
+        `http.https://github.com/.extraheader AUTHORIZATION: basic ${basicCredential}`
+      )
+    ).toBeGreaterThanOrEqual(0)
+
+    // Verify the includeIf entries point to the credentials file
+    const containerCredentialsPath = path.posix.join(
+      '/github/runner_temp',
+      path.basename(credentialsFilePath)
+    )
+    expect(
+      localConfigContent.indexOf(credentialsFilePath)
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      localConfigContent.indexOf(containerCredentialsPath)
+    ).toBeGreaterThanOrEqual(0)

    // Act
    await authHelper.removeAuth()

-    // Assert git config
-    gitConfigContent = (
+    // Assert all includeIf entries removed from local git config
+    localConfigContent = (
      await fs.promises.readFile(localGitConfigPath)
    ).toString()
-    expect(gitConfigContent.indexOf('http.')).toBeLessThan(0)
+    expect(localConfigContent.indexOf('includeIf.gitdir:')).toBeLessThan(0)
+    expect(
+      localConfigContent.indexOf(`includeIf.gitdir:${hostGitDir}.path`)
+    ).toBeLessThan(0)
+    expect(
+      localConfigContent.indexOf('includeIf.gitdir:/github/workspace/.git.path')
+    ).toBeLessThan(0)
+    expect(localConfigContent.indexOf(credentialsFilePath)).toBeLessThan(0)
+    expect(localConfigContent.indexOf(containerCredentialsPath)).toBeLessThan(0)
+
+    // Assert credentials config file deleted
+    credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBe(0)
+
+    // Verify credentials file no longer exists on disk
+    try {
+      await fs.promises.stat(credentialsFilePath)
+      throw new Error('Credentials file should have been deleted')
+    } catch (err) {
+      if ((err as any)?.code !== 'ENOENT') {
+        throw err
+      }
+    }
+  })
+
+  const removeAuth_removesTokenFromSubmodules =
+    'removeAuth removes token from submodules'
+  it(removeAuth_removesTokenFromSubmodules, async () => {
+    // Arrange
+    await setup(removeAuth_removesTokenFromSubmodules)
+
+    // Create fake submodule config paths
+    const submodule1Dir = path.join(workspace, '.git', 'modules', 'submodule-1')
+    const submodule2Dir = path.join(workspace, '.git', 'modules', 'submodule-2')
+    const submodule1ConfigPath = path.join(submodule1Dir, 'config')
+    const submodule2ConfigPath = path.join(submodule2Dir, 'config')
+
+    await fs.promises.mkdir(submodule1Dir, {recursive: true})
+    await fs.promises.mkdir(submodule2Dir, {recursive: true})
+    await fs.promises.writeFile(submodule1ConfigPath, '')
+    await fs.promises.writeFile(submodule2ConfigPath, '')
+
+    // Mock getSubmoduleConfigPaths to return our fake submodules (for both configure and remove)
+    const mockGetSubmoduleConfigPaths =
+      git.getSubmoduleConfigPaths as jest.Mock<any, any>
+    mockGetSubmoduleConfigPaths.mockResolvedValue([
+      submodule1ConfigPath,
+      submodule2ConfigPath
+    ])
+
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+    await authHelper.configureAuth()
+    await authHelper.configureSubmoduleAuth()
+
+    // Verify credentials file exists
+    let credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBe(1)
+    const credentialsFilePath = path.join(runnerTemp, credentialsFiles[0])
+
+    // Verify submodule 1 config has includeIf entries
+    let submodule1Content = (
+      await fs.promises.readFile(submodule1ConfigPath)
+    ).toString()
+    const submodule1GitDir = submodule1Dir.replace(/\\/g, '/')
+    expect(
+      submodule1Content.indexOf(`includeIf.gitdir:${submodule1GitDir}.path`)
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      submodule1Content.indexOf(credentialsFilePath)
+    ).toBeGreaterThanOrEqual(0)
+
+    // Verify submodule 2 config has includeIf entries
+    let submodule2Content = (
+      await fs.promises.readFile(submodule2ConfigPath)
+    ).toString()
+    const submodule2GitDir = submodule2Dir.replace(/\\/g, '/')
+    expect(
+      submodule2Content.indexOf(`includeIf.gitdir:${submodule2GitDir}.path`)
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      submodule2Content.indexOf(credentialsFilePath)
+    ).toBeGreaterThanOrEqual(0)
+
+    // Verify both host and container paths are in each submodule config
+    const containerCredentialsPath = path.posix.join(
+      '/github/runner_temp',
+      path.basename(credentialsFilePath)
+    )
+    expect(
+      submodule1Content.indexOf(containerCredentialsPath)
+    ).toBeGreaterThanOrEqual(0)
+    expect(
+      submodule2Content.indexOf(containerCredentialsPath)
+    ).toBeGreaterThanOrEqual(0)
+
+    // Act - ensure mock persists for removeAuth
+    mockGetSubmoduleConfigPaths.mockResolvedValue([
+      submodule1ConfigPath,
+      submodule2ConfigPath
+    ])
+    await authHelper.removeAuth()
+
+    // Assert submodule 1 includeIf entries removed
+    submodule1Content = (
+      await fs.promises.readFile(submodule1ConfigPath)
+    ).toString()
+    expect(submodule1Content.indexOf('includeIf.gitdir:')).toBeLessThan(0)
+    expect(submodule1Content.indexOf(credentialsFilePath)).toBeLessThan(0)
+    expect(submodule1Content.indexOf(containerCredentialsPath)).toBeLessThan(0)
+
+    // Assert submodule 2 includeIf entries removed
+    submodule2Content = (
+      await fs.promises.readFile(submodule2ConfigPath)
+    ).toString()
+    expect(submodule2Content.indexOf('includeIf.gitdir:')).toBeLessThan(0)
+    expect(submodule2Content.indexOf(credentialsFilePath)).toBeLessThan(0)
+    expect(submodule2Content.indexOf(containerCredentialsPath)).toBeLessThan(0)
+
+    // Assert credentials config file deleted
+    credentialsFiles = (await fs.promises.readdir(runnerTemp)).filter(
+      f => f.startsWith('git-credentials-') && f.endsWith('.config')
+    )
+    expect(credentialsFiles.length).toBe(0)
+
+    // Verify credentials file no longer exists on disk
+    try {
+      await fs.promises.stat(credentialsFilePath)
+      throw new Error('Credentials file should have been deleted')
+    } catch (err) {
+      if ((err as any)?.code !== 'ENOENT') {
+        throw err
+      }
+    }
  })

  const removeGlobalConfig_removesOverride =
@@ -701,6 +928,52 @@ describe('git-auth-helper tests', () => {
      }
    }
  })
+
+  const testCredentialsConfigPath_matchesCredentialsConfigPaths =
+    'testCredentialsConfigPath matches credentials config paths'
+  it(testCredentialsConfigPath_matchesCredentialsConfigPaths, async () => {
+    // Arrange
+    await setup(testCredentialsConfigPath_matchesCredentialsConfigPaths)
+    const authHelper = gitAuthHelper.createAuthHelper(git, settings)
+
+    // Get a real credentials config path
+    const credentialsConfigPath = await (
+      authHelper as any
+    ).getCredentialsConfigPath()
+
+    // Act & Assert
+    expect(
+      (authHelper as any).testCredentialsConfigPath(credentialsConfigPath)
+    ).toBe(true)
+    expect(
+      (authHelper as any).testCredentialsConfigPath(
+        '/some/path/git-credentials-12345678-abcd-1234-5678-123456789012.config'
+      )
+    ).toBe(true)
+    expect(
+      (authHelper as any).testCredentialsConfigPath(
+        '/some/path/git-credentials-abcdef12-3456-7890-abcd-ef1234567890.config'
+      )
+    ).toBe(true)
+
+    // Test invalid paths
+    expect(
+      (authHelper as any).testCredentialsConfigPath(
+        '/some/path/other-config.config'
+      )
+    ).toBe(false)
+    expect(
+      (authHelper as any).testCredentialsConfigPath(
+        '/some/path/git-credentials-invalid.config'
+      )
+    ).toBe(false)
+    expect(
+      (authHelper as any).testCredentialsConfigPath(
+        '/some/path/git-credentials-.config'
+      )
+    ).toBe(false)
+    expect((authHelper as any).testCredentialsConfigPath('')).toBe(false)
+  })
 })

 async function setup(testName: string): Promise<void> {
@@ -715,6 +988,7 @@ async function setup(testName: string): Promise<void> {
  await fs.promises.mkdir(tempHomedir, {recursive: true})
  process.env['RUNNER_TEMP'] = runnerTemp
  process.env['HOME'] = tempHomedir
+  process.env['GITHUB_WORKSPACE'] = workspace

  // Create git config
  globalGitConfigPath = path.join(tempHomedir, '.gitconfig')
@@ -733,10 +1007,20 @@ async function setup(testName: string): Promise<void> {
    checkout: jest.fn(),
    checkoutDetach: jest.fn(),
    config: jest.fn(
-      async (key: string, value: string, globalConfig?: boolean) => {
-        const configPath = globalConfig
-          ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
-          : localGitConfigPath
+      async (
+        key: string,
+        value: string,
+        globalConfig?: boolean,
+        add?: boolean,
+        configFile?: string
+      ) => {
+        const configPath =
+          configFile ||
+          (globalConfig
+            ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+            : localGitConfigPath)
+        // Ensure directory exists
+        await fs.promises.mkdir(path.dirname(configPath), {recursive: true})
        await fs.promises.appendFile(configPath, `\n${key} ${value}`)
      }
    ),
@@ -756,6 +1040,7 @@ async function setup(testName: string): Promise<void> {
    env: {},
    fetch: jest.fn(),
    getDefaultBranch: jest.fn(),
+    getSubmoduleConfigPaths: jest.fn(async () => []),
    getWorkingDirectory: jest.fn(() => workspace),
    init: jest.fn(),
    isDetached: jest.fn(),
@@ -794,8 +1079,72 @@ async function setup(testName: string): Promise<void> {
        return true
      }
    ),
+    tryConfigUnsetValue: jest.fn(
+      async (
+        key: string,
+        value: string,
+        globalConfig?: boolean,
+        configPath?: string
+      ): Promise<boolean> => {
+        const targetConfigPath =
+          configPath ||
+          (globalConfig
+            ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+            : localGitConfigPath)
+        let content = await fs.promises.readFile(targetConfigPath)
+        let lines = content
+          .toString()
+          .split('\n')
+          .filter(x => x)
+          .filter(x => !(x.startsWith(key) && x.includes(value)))
+        await fs.promises.writeFile(targetConfigPath, lines.join('\n'))
+        return true
+      }
+    ),
    tryDisableAutomaticGarbageCollection: jest.fn(),
    tryGetFetchUrl: jest.fn(),
+    tryGetConfigValues: jest.fn(
+      async (
+        key: string,
+        globalConfig?: boolean,
+        configPath?: string
+      ): Promise<string[]> => {
+        const targetConfigPath =
+          configPath ||
+          (globalConfig
+            ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+            : localGitConfigPath)
+        const content = await fs.promises.readFile(targetConfigPath)
+        const lines = content
+          .toString()
+          .split('\n')
+          .filter(x => x && x.startsWith(key))
+          .map(x => x.substring(key.length).trim())
+        return lines
+      }
+    ),
+    tryGetConfigKeys: jest.fn(
+      async (
+        pattern: string,
+        globalConfig?: boolean,
+        configPath?: string
+      ): Promise<string[]> => {
+        const targetConfigPath =
+          configPath ||
+          (globalConfig
+            ? path.join(git.env['HOME'] || tempHomedir, '.gitconfig')
+            : localGitConfigPath)
+        const content = await fs.promises.readFile(targetConfigPath)
+        const lines = content
+          .toString()
+          .split('\n')
+          .filter(x => x)
+        const keys = lines
+          .filter(x => new RegExp(pattern).test(x.split(' ')[0]))
+          .map(x => x.split(' ')[0])
+        return [...new Set(keys)] // Remove duplicates
+      }
+    ),
    tryReset: jest.fn(),
    version: jest.fn()
  }
@@ -824,12 +1173,14 @@ async function setup(testName: string): Promise<void> {
    sshUser: '',
    workflowOrganizationId: 123456,
    setSafeDirectory: true,
-    githubServerUrl: githubServerUrl
+    githubServerUrl: githubServerUrl,
+    allowUnsafePrCheckout: false
  }
 }

 async function getActualSshKeyPath(): Promise<string> {
  let actualTempFiles = (await fs.promises.readdir(runnerTemp))
+    .filter(x => !x.startsWith('git-credentials-')) // Exclude credentials config file
    .sort()
    .map(x => path.join(runnerTemp, x))
  if (actualTempFiles.length === 0) {
@@ -843,6 +1194,7 @@ async function getActualSshKeyPath(): Promise<string> {

 async function getActualSshKnownHostsPath(): Promise<string> {
  let actualTempFiles = (await fs.promises.readdir(runnerTemp))
+    .filter(x => !x.startsWith('git-credentials-')) // Exclude credentials config file
    .sort()
    .map(x => path.join(runnerTemp, x))
  if (actualTempFiles.length === 0) {
@@ -108,7 +108,7 @@ describe('Test fetchDepth and fetchTags options', () => {
    jest.restoreAllMocks()
  })

-  it('should call execGit with the correct arguments when fetchDepth is 0 and fetchTags is true', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 0', async () => {
    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
    const workingDirectory = 'test'
    const lfs = false
@@ -122,45 +122,7 @@ describe('Test fetchDepth and fetchTags options', () => {
    const refSpec = ['refspec1', 'refspec2']
    const options = {
      filter: 'filterValue',
-      fetchDepth: 0,
-      fetchTags: true
-    }
-
-    await git.fetch(refSpec, options)
-
-    expect(mockExec).toHaveBeenCalledWith(
-      expect.any(String),
-      [
-        '-c',
-        'protocol.version=2',
-        'fetch',
-        '--prune',
-        '--no-recurse-submodules',
-        '--filter=filterValue',
-        'origin',
-        'refspec1',
-        'refspec2'
-      ],
-      expect.any(Object)
-    )
-  })
-
-  it('should call execGit with the correct arguments when fetchDepth is 0 and fetchTags is false', async () => {
-    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
-
-    const workingDirectory = 'test'
-    const lfs = false
-    const doSparseCheckout = false
-    git = await commandManager.createCommandManager(
-      workingDirectory,
-      lfs,
-      doSparseCheckout
-    )
-    const refSpec = ['refspec1', 'refspec2']
-    const options = {
-      filter: 'filterValue',
-      fetchDepth: 0,
-      fetchTags: false
+      fetchDepth: 0
    }

    await git.fetch(refSpec, options)
@@ -183,7 +145,45 @@ describe('Test fetchDepth and fetchTags options', () => {
    )
  })

-  it('should call execGit with the correct arguments when fetchDepth is 1 and fetchTags is false', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 0 and refSpec includes tags', async () => {
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
+    const options = {
+      filter: 'filterValue',
+      fetchDepth: 0
+    }
+
+    await git.fetch(refSpec, options)
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      [
+        '-c',
+        'protocol.version=2',
+        'fetch',
+        '--no-tags',
+        '--prune',
+        '--no-recurse-submodules',
+        '--filter=filterValue',
+        'origin',
+        'refspec1',
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
+      ],
+      expect.any(Object)
+    )
+  })
+
+  it('should call execGit with the correct arguments when fetchDepth is 1', async () => {
    jest.spyOn(exec, 'exec').mockImplementation(mockExec)

    const workingDirectory = 'test'
@@ -197,8 +197,7 @@ describe('Test fetchDepth and fetchTags options', () => {
    const refSpec = ['refspec1', 'refspec2']
    const options = {
      filter: 'filterValue',
-      fetchDepth: 1,
-      fetchTags: false
+      fetchDepth: 1
    }

    await git.fetch(refSpec, options)
@@ -222,7 +221,7 @@ describe('Test fetchDepth and fetchTags options', () => {
    )
  })

-  it('should call execGit with the correct arguments when fetchDepth is 1 and fetchTags is true', async () => {
+  it('should call execGit with the correct arguments when fetchDepth is 1 and refSpec includes tags', async () => {
    jest.spyOn(exec, 'exec').mockImplementation(mockExec)

    const workingDirectory = 'test'
@@ -233,11 +232,10 @@ describe('Test fetchDepth and fetchTags options', () => {
      lfs,
      doSparseCheckout
    )
-    const refSpec = ['refspec1', 'refspec2']
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
    const options = {
      filter: 'filterValue',
-      fetchDepth: 1,
-      fetchTags: true
+      fetchDepth: 1
    }

    await git.fetch(refSpec, options)
@@ -248,13 +246,15 @@ describe('Test fetchDepth and fetchTags options', () => {
        '-c',
        'protocol.version=2',
        'fetch',
+        '--no-tags',
        '--prune',
        '--no-recurse-submodules',
        '--filter=filterValue',
        '--depth=1',
        'origin',
        'refspec1',
-        'refspec2'
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
      ],
      expect.any(Object)
    )
@@ -338,7 +338,7 @@ describe('Test fetchDepth and fetchTags options', () => {
    )
  })

-  it('should call execGit with the correct arguments when fetchTags is true and showProgress is true', async () => {
+  it('should call execGit with the correct arguments when showProgress is true and refSpec includes tags', async () => {
    jest.spyOn(exec, 'exec').mockImplementation(mockExec)

    const workingDirectory = 'test'
@@ -349,10 +349,9 @@ describe('Test fetchDepth and fetchTags options', () => {
      lfs,
      doSparseCheckout
    )
-    const refSpec = ['refspec1', 'refspec2']
+    const refSpec = ['refspec1', 'refspec2', '+refs/tags/*:refs/tags/*']
    const options = {
      filter: 'filterValue',
-      fetchTags: true,
      showProgress: true
    }

@@ -364,15 +363,187 @@ describe('Test fetchDepth and fetchTags options', () => {
        '-c',
        'protocol.version=2',
        'fetch',
+        '--no-tags',
        '--prune',
        '--no-recurse-submodules',
        '--progress',
        '--filter=filterValue',
        'origin',
        'refspec1',
-        'refspec2'
+        'refspec2',
+        '+refs/tags/*:refs/tags/*'
      ],
      expect.any(Object)
    )
  })
 })
+
+describe('repository initialization object format', () => {
+  beforeEach(async () => {
+    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
+    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+  })
+
+  it('initializes SHA-256 repositories with the matching object format', async () => {
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('git version 2.50.1'))
+      }
+
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    git = await commandManager.createCommandManager('test', false, false)
+
+    await git.init('sha256')
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      ['init', '--object-format=sha256', 'test'],
+      expect.any(Object)
+    )
+  })
+
+  it('initializes SHA-1 repositories with existing default arguments', async () => {
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('git version 2.50.1'))
+      }
+
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    git = await commandManager.createCommandManager('test', false, false)
+
+    await git.init('sha1')
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      ['init', 'test'],
+      expect.any(Object)
+    )
+  })
+})
+
+describe('git user-agent with orchestration ID', () => {
+  beforeEach(async () => {
+    jest.spyOn(fshelper, 'fileExistsSync').mockImplementation(jest.fn())
+    jest.spyOn(fshelper, 'directoryExistsSync').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+    // Clean up environment variable to prevent test pollution
+    delete process.env['ACTIONS_ORCHESTRATION_ID']
+  })
+
+  it('should include orchestration ID in user-agent when ACTIONS_ORCHESTRATION_ID is set', async () => {
+    const orchId = 'test-orch-id-12345'
+    process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent includes the orchestration ID
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      `git/2.18 (github-actions-checkout) actions_orchestration_id/${orchId}`
+    )
+  })
+
+  it('should sanitize invalid characters in orchestration ID', async () => {
+    const orchId = 'test (with) special/chars'
+    process.env['ACTIONS_ORCHESTRATION_ID'] = orchId
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent has sanitized orchestration ID (spaces, parentheses, slash replaced)
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      'git/2.18 (github-actions-checkout) actions_orchestration_id/test__with__special_chars'
+    )
+  })
+
+  it('should not modify user-agent when ACTIONS_ORCHESTRATION_ID is not set', async () => {
+    delete process.env['ACTIONS_ORCHESTRATION_ID']
+
+    let capturedEnv: any = null
+    mockExec.mockImplementation((path, args, options) => {
+      if (args.includes('version')) {
+        options.listeners.stdout(Buffer.from('2.18'))
+      }
+      // Capture env on any command
+      capturedEnv = options.env
+      return 0
+    })
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+
+    // Call a git command to trigger env capture after user-agent is set
+    await git.init()
+
+    // Verify the user agent does NOT contain orchestration ID
+    expect(git).toBeDefined()
+    expect(capturedEnv).toBeDefined()
+    expect(capturedEnv['GIT_HTTP_USER_AGENT']).toBe(
+      'git/2.18 (github-actions-checkout)'
+    )
+  })
+})
@@ -471,6 +471,7 @@ async function setup(testName: string): Promise<void> {
    configExists: jest.fn(),
    fetch: jest.fn(),
    getDefaultBranch: jest.fn(),
+    getSubmoduleConfigPaths: jest.fn(async () => []),
    getWorkingDirectory: jest.fn(() => repositoryPath),
    init: jest.fn(),
    isDetached: jest.fn(),
@@ -493,12 +494,15 @@ async function setup(testName: string): Promise<void> {
      return true
    }),
    tryConfigUnset: jest.fn(),
+    tryConfigUnsetValue: jest.fn(),
    tryDisableAutomaticGarbageCollection: jest.fn(),
    tryGetFetchUrl: jest.fn(async () => {
      // Sanity check - this function shouldn't be called when the .git directory doesn't exist
      await fs.promises.stat(path.join(repositoryPath, '.git'))
      return repositoryUrl
    }),
+    tryGetConfigValues: jest.fn(),
+    tryGetConfigKeys: jest.fn(),
    tryReset: jest.fn(async () => {
      return true
    }),
@@ -0,0 +1,98 @@
+import * as core from '@actions/core'
+import * as github from '@actions/github'
+import * as githubApiHelper from '../lib/github-api-helper'
+
+describe('github-api-helper object format', () => {
+  let getOctokitSpy: jest.SpyInstance
+  let debugSpy: jest.SpyInstance
+  let request: jest.Mock
+
+  function mockHashAlgorithmApi(hashAlgorithm: string): void {
+    request = jest.fn(async () => ({
+      data: {
+        hash_algorithm: hashAlgorithm
+      }
+    }))
+    getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+      request
+    } as any)
+  }
+
+  beforeEach(() => {
+    debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+  })
+
+  it('detects SHA-256 from the repository hash algorithm endpoint', async () => {
+    mockHashAlgorithmApi('sha256')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: 'sha256', succeeded: true})
+
+    expect(getOctokitSpy).toHaveBeenCalledWith(
+      'token',
+      expect.objectContaining({baseUrl: 'https://api.github.com'})
+    )
+    expect(request).toHaveBeenCalledWith(
+      'GET /repos/{owner}/{repo}/hash-algorithm',
+      {owner: 'owner', repo: 'repo'}
+    )
+  })
+
+  it('detects SHA-1 from the repository hash algorithm endpoint', async () => {
+    mockHashAlgorithmApi('sha1')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: 'sha1', succeeded: true})
+  })
+
+  it('detects object format from an existing commit without API calls', async () => {
+    const commitSha =
+      '9422233ca7ee1b17f1e905d0e141faf0c401556c41cdc6acd71c6bd685da2e92'
+    getOctokitSpy = jest.spyOn(github, 'getOctokit')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat(
+        'token',
+        'owner',
+        'repo',
+        undefined,
+        commitSha
+      )
+    ).resolves.toEqual({format: 'sha256', succeeded: true})
+
+    expect(getOctokitSpy).not.toHaveBeenCalled()
+  })
+
+  it('returns unsuccessful when the hash algorithm endpoint value is not recognized', async () => {
+    mockHashAlgorithmApi('unknown')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: '', succeeded: false})
+    expect(debugSpy).toHaveBeenCalledWith(
+      'Unable to determine repository object format from hash-algorithm endpoint'
+    )
+  })
+
+  it('returns unsuccessful when the hash algorithm API lookup fails', async () => {
+    request = jest.fn(async () => {
+      throw new Error('not found')
+    })
+    jest.spyOn(github, 'getOctokit').mockReturnValue({
+      request
+    } as any)
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: '', succeeded: false})
+    expect(debugSpy).toHaveBeenCalledWith(
+      'Unable to determine repository object format from hash-algorithm endpoint: not found'
+    )
+  })
+})
@@ -91,6 +91,7 @@ describe('input-helper tests', () => {
    expect(settings.repositoryOwner).toBe('some-owner')
    expect(settings.repositoryPath).toBe(gitHubWorkspace)
    expect(settings.setSafeDirectory).toBe(true)
+    expect(settings.allowUnsafePrCheckout).toBe(false)
  })

  it('qualifies ref', async () => {
@@ -133,6 +134,16 @@ describe('input-helper tests', () => {
    expect(settings.commit).toBe('1111111111222222222233333333334444444444')
  })

+  it('sets ref to empty when explicit sha-256', async () => {
+    inputs.ref =
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    const settings: IGitSourceSettings = await inputHelper.getInputs()
+    expect(settings.ref).toBeFalsy()
+    expect(settings.commit).toBe(
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    )
+  })
+
  it('sets sha to empty when explicit ref', async () => {
    inputs.ref = 'refs/heads/some-other-ref'
    const settings: IGitSourceSettings = await inputHelper.getInputs()
@@ -1,8 +1,12 @@
 import * as assert from 'assert'
+import * as core from '@actions/core'
+import * as github from '@actions/github'
 import * as refHelper from '../lib/ref-helper'
 import {IGitCommandManager} from '../lib/git-command-manager'

 const commit = '1234567890123456789012345678901234567890'
+const sha256Commit =
+  '1234567890123456789012345678901234567890123456789012345678901234'
 let git: IGitCommandManager

 describe('ref-helper tests', () => {
@@ -37,6 +41,12 @@ describe('ref-helper tests', () => {
    expect(checkoutInfo.startPoint).toBeFalsy()
  })

+  it('getCheckoutInfo sha-256 only', async () => {
+    const checkoutInfo = await refHelper.getCheckoutInfo(git, '', sha256Commit)
+    expect(checkoutInfo.ref).toBe(sha256Commit)
+    expect(checkoutInfo.startPoint).toBeFalsy()
+  })
+
  it('getCheckoutInfo refs/heads/', async () => {
    const checkoutInfo = await refHelper.getCheckoutInfo(
      git,
@@ -152,7 +162,22 @@ describe('ref-helper tests', () => {
  it('getRefSpec sha + refs/tags/', async () => {
    const refSpec = refHelper.getRefSpec('refs/tags/my-tag', commit)
    expect(refSpec.length).toBe(1)
-    expect(refSpec[0]).toBe(`+${commit}:refs/tags/my-tag`)
+    expect(refSpec[0]).toBe(`+refs/tags/my-tag:refs/tags/my-tag`)
+  })
+
+  it('getRefSpec sha + refs/tags/ with fetchTags', async () => {
+    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
+    const refSpec = refHelper.getRefSpec('refs/tags/my-tag', commit, true)
+    expect(refSpec.length).toBe(1)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+  })
+
+  it('getRefSpec sha + refs/heads/ with fetchTags', async () => {
+    // When fetchTags is true, include both the branch refspec and tags wildcard
+    const refSpec = refHelper.getRefSpec('refs/heads/my/branch', commit, true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe(`+${commit}:refs/remotes/origin/my/branch`)
  })

  it('getRefSpec sha only', async () => {
@@ -168,6 +193,14 @@ describe('ref-helper tests', () => {
    expect(refSpec[1]).toBe('+refs/tags/my-ref*:refs/tags/my-ref*')
  })

+  it('getRefSpec unqualified ref only with fetchTags', async () => {
+    // When fetchTags is true, skip specific tag pattern since wildcard covers all
+    const refSpec = refHelper.getRefSpec('my-ref', '', true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe('+refs/heads/my-ref*:refs/remotes/origin/my-ref*')
+  })
+
  it('getRefSpec refs/heads/ only', async () => {
    const refSpec = refHelper.getRefSpec('refs/heads/my/branch', '')
    expect(refSpec.length).toBe(1)
@@ -187,4 +220,159 @@ describe('ref-helper tests', () => {
    expect(refSpec.length).toBe(1)
    expect(refSpec[0]).toBe('+refs/tags/my-tag:refs/tags/my-tag')
  })
+
+  it('getRefSpec refs/tags/ only with fetchTags', async () => {
+    // When fetchTags is true, only include tags wildcard (specific tag is redundant)
+    const refSpec = refHelper.getRefSpec('refs/tags/my-tag', '', true)
+    expect(refSpec.length).toBe(1)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+  })
+
+  it('getRefSpec refs/heads/ only with fetchTags', async () => {
+    // When fetchTags is true, include both the branch refspec and tags wildcard
+    const refSpec = refHelper.getRefSpec('refs/heads/my/branch', '', true)
+    expect(refSpec.length).toBe(2)
+    expect(refSpec[0]).toBe('+refs/tags/*:refs/tags/*')
+    expect(refSpec[1]).toBe(
+      '+refs/heads/my/branch:refs/remotes/origin/my/branch'
+    )
+  })
+
+  describe('checkCommitInfo', () => {
+    const repositoryOwner = 'some-owner'
+    const repositoryName = 'some-repo'
+    const ref = 'refs/pull/123/merge'
+    const sha1Head = '1111111111222222222233333333334444444444'
+    const sha1Base = 'aaaaaaaaaabbbbbbbbbbccccccccccdddddddddd'
+    const sha256Head =
+      '1111111111222222222233333333334444444444555555555566666666667777'
+    const sha256Base =
+      'aaaaaaaaaabbbbbbbbbbccccccccccddddddddddeeeeeeeeeeffffffffff0000'
+    let debugSpy: jest.SpyInstance
+    let getOctokitSpy: jest.SpyInstance
+    let repoGetSpy: jest.Mock
+    let originalEventName: string
+    let originalPayload: unknown
+    let originalRef: string
+    let originalSha: string
+
+    function setPullRequestContext(
+      expectedHeadSha: string,
+      expectedBaseSha: string,
+      mergeCommit: string
+    ): void {
+      ;(github.context as any).eventName = 'pull_request'
+      github.context.ref = ref
+      github.context.sha = mergeCommit
+      ;(github.context as any).payload = {
+        action: 'synchronize',
+        after: expectedHeadSha,
+        number: 123,
+        pull_request: {
+          base: {
+            sha: expectedBaseSha
+          }
+        },
+        repository: {
+          private: false
+        }
+      }
+    }
+
+    beforeEach(() => {
+      originalEventName = github.context.eventName
+      originalPayload = github.context.payload
+      originalRef = github.context.ref
+      originalSha = github.context.sha
+
+      jest.spyOn(github.context, 'repo', 'get').mockReturnValue({
+        owner: repositoryOwner,
+        repo: repositoryName
+      })
+      debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+      repoGetSpy = jest.fn(async () => ({}))
+      getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+        rest: {
+          repos: {
+            get: repoGetSpy
+          }
+        }
+      } as any)
+    })
+
+    afterEach(() => {
+      ;(github.context as any).eventName = originalEventName
+      ;(github.context as any).payload = originalPayload
+      github.context.ref = originalRef
+      github.context.sha = originalSha
+      jest.restoreAllMocks()
+    })
+
+    it('returns early for SHA-1 merge commit', async () => {
+      setPullRequestContext(sha1Head, sha1Base, commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${sha1Head} into ${sha1Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        commit
+      )
+
+      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(repoGetSpy).not.toHaveBeenCalled()
+    })
+
+    it('matches SHA-256 merge commit info', async () => {
+      const actualHeadSha =
+        '9999999999888888888877777777776666666666555555555544444444443333'
+      setPullRequestContext(sha256Head, sha256Base, sha256Commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${actualHeadSha} into ${sha256Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        sha256Commit
+      )
+
+      expect(getOctokitSpy).toHaveBeenCalledWith(
+        'token',
+        expect.objectContaining({
+          userAgent: expect.stringContaining(
+            `expected_head_sha=${sha256Head};actual_head_sha=${actualHeadSha}`
+          )
+        })
+      )
+      expect(repoGetSpy).toHaveBeenCalledWith({
+        owner: repositoryOwner,
+        repo: repositoryName
+      })
+      expect(debugSpy).toHaveBeenCalledWith(
+        `Expected head sha ${sha256Head}; actual head sha ${actualHeadSha}`
+      )
+      expect(debugSpy).not.toHaveBeenCalledWith('Unexpected message format')
+    })
+
+    it('does not match 50-char hex as a valid merge', async () => {
+      const invalidHeadSha =
+        '99999999998888888888777777777766666666665555555555'
+      setPullRequestContext(sha1Head, sha1Base, commit)
+
+      await refHelper.checkCommitInfo(
+        'token',
+        `Merge ${invalidHeadSha} into ${sha1Base}`,
+        repositoryOwner,
+        repositoryName,
+        ref,
+        commit
+      )
+
+      expect(getOctokitSpy).not.toHaveBeenCalled()
+      expect(repoGetSpy).not.toHaveBeenCalled()
+      expect(debugSpy).toHaveBeenCalledWith('Unexpected message format')
+    })
+  })
 })
@@ -0,0 +1,254 @@
+import * as github from '@actions/github'
+import {assertSafePrCheckout} from '../lib/unsafe-pr-checkout-helper'
+
+// Shallow clone original @actions/github context
+const originalContext = {...github.context}
+const originalEventName = github.context.eventName
+const originalPayload = github.context.payload
+
+const BASE_REPO_ID = 100
+const FORK_REPO_ID = 200
+const PR_HEAD_SHA = '1111111111111111111111111111111111111111'
+const PR_MERGE_SHA = '2222222222222222222222222222222222222222'
+const SAFE_BASE_SHA = '3333333333333333333333333333333333333333'
+const WORKFLOW_RUN_HEAD_COMMIT_SHA = '4444444444444444444444444444444444444444'
+const BASE_QUALIFIED_REPO = 'some-owner/some-repo'
+
+function setContext(eventName: string, payload: object): void {
+  ;(github.context as {eventName: string}).eventName = eventName
+  ;(github.context as {payload: object}).payload = payload
+}
+
+function forkPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: FORK_REPO_ID}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function sameRepoPullRequestTargetPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    pull_request: {
+      head: {
+        sha: PR_HEAD_SHA,
+        repo: {id: BASE_REPO_ID}
+      },
+      merge_commit_sha: PR_MERGE_SHA
+    }
+  }
+}
+
+function forkWorkflowRunPayload(): object {
+  return {
+    repository: {id: BASE_REPO_ID},
+    workflow_run: {
+      event: 'pull_request',
+      head_commit: {id: WORKFLOW_RUN_HEAD_COMMIT_SHA},
+      head_repository: {id: FORK_REPO_ID}
+    }
+  }
+}
+
+describe('unsafe-pr-checkout-helper', () => {
+  beforeAll(() => {
+    jest.spyOn(github.context, 'repo', 'get').mockReturnValue({
+      owner: 'some-owner',
+      repo: 'some-repo'
+    })
+  })
+
+  afterEach(() => {
+    ;(github.context as {eventName: string}).eventName = originalEventName
+    ;(github.context as {payload: object}).payload = originalPayload
+  })
+
+  afterAll(() => {
+    ;(github.context as {eventName: string}).eventName =
+      originalContext.eventName
+    ;(github.context as {payload: object}).payload = originalContext.payload
+    jest.restoreAllMocks()
+  })
+
+  it('allows pull_request events untouched', () => {
+    setContext('pull_request', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'attacker/fork',
+        ref: 'refs/pull/1/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows pull_request_target default checkout (base branch)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/heads/main',
+        commit: SAFE_BASE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('allows same-repo pull_request_target checkout of PR head', () => {
+    setContext('pull_request_target', sameRepoPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses pull_request_target fork PR head SHA checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/Refusing to check out fork pull request code/)
+  })
+
+  it('refuses pull_request_target fork PR merge_commit_sha checkout', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_MERGE_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow(/allow-unsafe-pr-checkout/)
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (head)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/head',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target fork PR ref pattern (merge)', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target when repository points at the fork', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'attacker/fork',
+        ref: 'refs/heads/main',
+        commit: '',
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target ignoring repository case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: 'SOME-OWNER/SOME-REPO',
+        ref: '',
+        commit: PR_HEAD_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses pull_request_target ignoring commit SHA case differences', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: PR_HEAD_SHA.toUpperCase(),
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows pull_request_target fork PR checkout when opted in', () => {
+    setContext('pull_request_target', forkPullRequestTargetPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: 'refs/pull/42/merge',
+        commit: '',
+        allowUnsafePrCheckout: true
+      })
+    ).not.toThrow()
+  })
+
+  it('refuses workflow_run fork PR head_commit.id checkout', () => {
+    setContext('workflow_run', forkWorkflowRunPayload())
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('refuses workflow_run with pull_request_target underlying event', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {event: string}
+    }
+    payload.workflow_run.event = 'pull_request_target'
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).toThrow()
+  })
+
+  it('allows workflow_run same-repo PR (head_repository.id matches base)', () => {
+    const payload = forkWorkflowRunPayload() as {
+      workflow_run: {head_repository: {id: number}}
+    }
+    payload.workflow_run.head_repository.id = BASE_REPO_ID
+    setContext('workflow_run', payload)
+    expect(() =>
+      assertSafePrCheckout({
+        qualifiedRepository: BASE_QUALIFIED_REPO,
+        ref: '',
+        commit: WORKFLOW_RUN_HEAD_COMMIT_SHA,
+        allowUnsafePrCheckout: false
+      })
+    ).not.toThrow()
+  })
+})
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+# Verify tags were fetched
+TAG_COUNT=$(git -C ./fetch-tags-test tag | wc -l)
+if [ "$TAG_COUNT" -eq 0 ]; then
+    echo "Expected tags to be fetched, but found none"
+    exit 1
+fi
+echo "Found $TAG_COUNT tags"
@@ -17,7 +17,7 @@ fi

 echo "Testing persisted credential"
 pushd ./submodules-recursive/submodule-level-1/submodule-level-2
-git config --local --name-only --get-regexp http.+extraheader && git fetch
+git config --local --includes --name-only --get-regexp http.+extraheader && git fetch
 if [ "$?" != "0" ]; then
    echo "Failed to validate persisted credential"
    popd
@@ -17,7 +17,7 @@ fi

 echo "Testing persisted credential"
 pushd ./submodules-true/submodule-level-1
-git config --local --name-only --get-regexp http.+extraheader && git fetch
+git config --local --includes --name-only --get-regexp http.+extraheader && git fetch
 if [ "$?" != "0" ]; then
    echo "Failed to validate persisted credential"
    popd
@@ -0,0 +1,51 @@
+#!/bin/bash
+set -e
+
+# Verify worktree credentials
+# This test verifies that git credentials work in worktrees created after checkout
+# Usage: verify-worktree.sh <checkout-path> <worktree-name>
+
+CHECKOUT_PATH="$1"
+WORKTREE_NAME="$2"
+
+if [ -z "$CHECKOUT_PATH" ] || [ -z "$WORKTREE_NAME" ]; then
+  echo "Usage: verify-worktree.sh <checkout-path> <worktree-name>"
+  exit 1
+fi
+
+cd "$CHECKOUT_PATH"
+
+# Add safe directory for container environments
+git config --global --add safe.directory "*" 2>/dev/null || true
+
+# Show the includeIf configuration
+echo "Git config includeIf entries:"
+git config --list --show-origin | grep -i include || true
+
+# Create the worktree
+echo "Creating worktree..."
+git worktree add "../$WORKTREE_NAME" HEAD --detach
+
+# Change to worktree directory
+cd "../$WORKTREE_NAME"
+
+# Verify we're in a worktree
+echo "Verifying worktree gitdir:"
+cat .git
+
+# Verify credentials are available in worktree by checking extraheader is configured
+echo "Checking credentials in worktree..."
+if git config --list --show-origin | grep -q "extraheader"; then
+  echo "Credentials are configured in worktree"
+else
+  echo "ERROR: Credentials are NOT configured in worktree"
+  echo "Full git config:"
+  git config --list --show-origin
+  exit 1
+fi
+
+# Verify fetch works in the worktree
+echo "Fetching in worktree..."
+git fetch origin
+
+echo "Worktree credentials test passed!"
@@ -98,6 +98,12 @@ inputs:
  github-server-url:
    description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Example URLs are https://github.com or https://my-ghes-server.example.com
    required: false
+  allow-unsafe-pr-checkout:
+    description: >
+      Required to check out fork pull request code from a workflow triggered by
+      `pull_request_target` or `workflow_run`. See [Pwn Requests](todo:need-link)
+      for the risks. Set to `true` only after reviewing the risks.
+    default: false
 outputs:
  ref:
    description: 'The branch, tag or SHA that was checked out'
@@ -162,6 +162,7 @@ class GitAuthHelper {
        this.sshKeyPath = '';
        this.sshKnownHostsPath = '';
        this.temporaryHomePath = '';
+        this.credentialsConfigPath = ''; // Path to separate credentials config file in RUNNER_TEMP
        this.git = gitCommandManager;
        this.settings = gitSourceSettings || {};
        // Token auth header
@@ -229,15 +230,17 @@ class GitAuthHelper {
    configureGlobalAuth() {
        return __awaiter(this, void 0, void 0, function* () {
            // 'configureTempGlobalConfig' noops if already set, just returns the path
-            const newGitConfigPath = yield this.configureTempGlobalConfig();
+            yield this.configureTempGlobalConfig();
            try {
                // Configure the token
-                yield this.configureToken(newGitConfigPath, true);
+                yield this.configureToken(true);
                // Configure HTTPS instead of SSH
                yield this.git.tryConfigUnset(this.insteadOfKey, true);
                if (!this.settings.sshKey) {
                    for (const insteadOfValue of this.insteadOfValues) {
-                        yield this.git.config(this.insteadOfKey, insteadOfValue, true, true);
+                        yield this.git.config(this.insteadOfKey, insteadOfValue, true, // globalConfig?
+                        true // add?
+                        );
                    }
                }
            }
@@ -252,19 +255,34 @@ class GitAuthHelper {
    configureSubmoduleAuth() {
        return __awaiter(this, void 0, void 0, function* () {
            // Remove possible previous HTTPS instead of SSH
-            yield this.removeGitConfig(this.insteadOfKey, true);
+            yield this.removeSubmoduleGitConfig(this.insteadOfKey);
            if (this.settings.persistCredentials) {
-                // Configure a placeholder value. This approach avoids the credential being captured
-                // by process creation audit events, which are commonly logged. For more information,
-                // refer to https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
-                const output = yield this.git.submoduleForeach(
-                // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
-                `sh -c "git config --local '${this.tokenConfigKey}' '${this.tokenPlaceholderConfigValue}' && git config --local --show-origin --name-only --get-regexp remote.origin.url"`, this.settings.nestedSubmodules);
-                // Replace the placeholder
-                const configPaths = output.match(/(?<=(^|\n)file:)[^\t]+(?=\tremote\.origin\.url)/g) || [];
+                // Get the credentials config file path in RUNNER_TEMP
+                const credentialsConfigPath = this.getCredentialsConfigPath();
+                // Container credentials config path
+                const containerCredentialsPath = path.posix.join('/github/runner_temp', path.basename(credentialsConfigPath));
+                // Get submodule config file paths.
+                const configPaths = yield this.git.getSubmoduleConfigPaths(this.settings.nestedSubmodules);
+                // For each submodule, configure includeIf entries pointing to the shared credentials file.
+                // Configure both host and container paths to support Docker container actions.
                for (const configPath of configPaths) {
-                    core.debug(`Replacing token placeholder in '${configPath}'`);
-                    yield this.replaceTokenPlaceholder(configPath);
+                    // Submodule Git directory
+                    let submoduleGitDir = path.dirname(configPath); // The config file is at .git/modules/submodule-name/config
+                    submoduleGitDir = submoduleGitDir.replace(/\\/g, '/'); // Use forward slashes, even on Windows
+                    // Configure host includeIf
+                    yield this.git.config(`includeIf.gitdir:${submoduleGitDir}.path`, credentialsConfigPath, false, // globalConfig?
+                    false, // add?
+                    configPath);
+                    // Container submodule git directory
+                    const githubWorkspace = process.env['GITHUB_WORKSPACE'];
+                    assert.ok(githubWorkspace, 'GITHUB_WORKSPACE is not defined');
+                    let relativeSubmoduleGitDir = path.relative(githubWorkspace, submoduleGitDir);
+                    relativeSubmoduleGitDir = relativeSubmoduleGitDir.replace(/\\/g, '/'); // Use forward slashes, even on Windows
+                    const containerSubmoduleGitDir = path.posix.join('/github/workspace', relativeSubmoduleGitDir);
+                    // Configure container includeIf
+                    yield this.git.config(`includeIf.gitdir:${containerSubmoduleGitDir}.path`, containerCredentialsPath, false, // globalConfig?
+                    false, // add?
+                    configPath);
                }
                if (this.settings.sshKey) {
                    // Configure core.sshCommand
@@ -295,6 +313,10 @@ class GitAuthHelper {
            }
        });
    }
+    /**
+     * Configures SSH authentication by writing the SSH key and known hosts,
+     * and setting up the GIT_SSH_COMMAND environment variable.
+     */
    configureSsh() {
        return __awaiter(this, void 0, void 0, function* () {
            if (!this.settings.sshKey) {
@@ -351,43 +373,94 @@ class GitAuthHelper {
            }
        });
    }
-    configureToken(configPath, globalConfig) {
+    /**
+     * Configures token-based authentication by creating a credentials config file
+     * and setting up includeIf entries to reference it.
+     * @param globalConfig Whether to configure global config instead of local
+     */
+    configureToken(globalConfig) {
        return __awaiter(this, void 0, void 0, function* () {
-            // Validate args
-            assert.ok((configPath && globalConfig) || (!configPath && !globalConfig), 'Unexpected configureToken parameter combinations');
-            // Default config path
-            if (!configPath && !globalConfig) {
-                configPath = path.join(this.git.getWorkingDirectory(), '.git', 'config');
-            }
-            // Configure a placeholder value. This approach avoids the credential being captured
-            // by process creation audit events, which are commonly logged. For more information,
-            // refer to https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
-            yield this.git.config(this.tokenConfigKey, this.tokenPlaceholderConfigValue, globalConfig);
-            // Replace the placeholder
-            yield this.replaceTokenPlaceholder(configPath || '');
-        });
-    }
-    replaceTokenPlaceholder(configPath) {
-        return __awaiter(this, void 0, void 0, function* () {
-            assert.ok(configPath, 'configPath is not defined');
-            let content = (yield fs.promises.readFile(configPath)).toString();
+            // Get the credentials config file path in RUNNER_TEMP
+            const credentialsConfigPath = this.getCredentialsConfigPath();
+            // Write placeholder to the separate credentials config file using git config.
+            // This approach avoids the credential being captured by process creation audit events,
+            // which are commonly logged. For more information, refer to
+            // https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
+            yield this.git.config(this.tokenConfigKey, this.tokenPlaceholderConfigValue, false, // globalConfig?
+            false, // add?
+            credentialsConfigPath);
+            // Replace the placeholder in the credentials config file
+            let content = (yield fs.promises.readFile(credentialsConfigPath)).toString();
            const placeholderIndex = content.indexOf(this.tokenPlaceholderConfigValue);
            if (placeholderIndex < 0 ||
                placeholderIndex != content.lastIndexOf(this.tokenPlaceholderConfigValue)) {
-                throw new Error(`Unable to replace auth placeholder in ${configPath}`);
+                throw new Error(`Unable to replace auth placeholder in ${credentialsConfigPath}`);
            }
            assert.ok(this.tokenConfigValue, 'tokenConfigValue is not defined');
            content = content.replace(this.tokenPlaceholderConfigValue, this.tokenConfigValue);
-            yield fs.promises.writeFile(configPath, content);
+            yield fs.promises.writeFile(credentialsConfigPath, content);
+            // Add include or includeIf to reference the credentials config
+            if (globalConfig) {
+                // Global config file is temporary
+                yield this.git.config('include.path', credentialsConfigPath, true // globalConfig?
+                );
+            }
+            else {
+                // Host git directory
+                let gitDir = path.join(this.git.getWorkingDirectory(), '.git');
+                gitDir = gitDir.replace(/\\/g, '/'); // Use forward slashes, even on Windows
+                // Configure host includeIf
+                const hostIncludeKey = `includeIf.gitdir:${gitDir}.path`;
+                yield this.git.config(hostIncludeKey, credentialsConfigPath);
+                // Configure host includeIf for worktrees
+                const hostWorktreeIncludeKey = `includeIf.gitdir:${gitDir}/worktrees/*.path`;
+                yield this.git.config(hostWorktreeIncludeKey, credentialsConfigPath);
+                // Container git directory
+                const workingDirectory = this.git.getWorkingDirectory();
+                const githubWorkspace = process.env['GITHUB_WORKSPACE'];
+                assert.ok(githubWorkspace, 'GITHUB_WORKSPACE is not defined');
+                let relativePath = path.relative(githubWorkspace, workingDirectory);
+                relativePath = relativePath.replace(/\\/g, '/'); // Use forward slashes, even on Windows
+                const containerGitDir = path.posix.join('/github/workspace', relativePath, '.git');
+                // Container credentials config path
+                const containerCredentialsPath = path.posix.join('/github/runner_temp', path.basename(credentialsConfigPath));
+                // Configure container includeIf
+                const containerIncludeKey = `includeIf.gitdir:${containerGitDir}.path`;
+                yield this.git.config(containerIncludeKey, containerCredentialsPath);
+                // Configure container includeIf for worktrees
+                const containerWorktreeIncludeKey = `includeIf.gitdir:${containerGitDir}/worktrees/*.path`;
+                yield this.git.config(containerWorktreeIncludeKey, containerCredentialsPath);
+            }
        });
    }
+    /**
+     * Gets or creates the path to the credentials config file in RUNNER_TEMP.
+     * @returns The absolute path to the credentials config file
+     */
+    getCredentialsConfigPath() {
+        if (this.credentialsConfigPath) {
+            return this.credentialsConfigPath;
+        }
+        const runnerTemp = process.env['RUNNER_TEMP'] || '';
+        assert.ok(runnerTemp, 'RUNNER_TEMP is not defined');
+        // Create a unique filename for this checkout instance
+        const configFileName = `git-credentials-${(0, uuid_1.v4)()}.config`;
+        this.credentialsConfigPath = path.join(runnerTemp, configFileName);
+        core.debug(`Credentials config path: ${this.credentialsConfigPath}`);
+        return this.credentialsConfigPath;
+    }
+    /**
+     * Removes SSH authentication configuration by cleaning up SSH keys,
+     * known hosts files, and SSH command configurations.
+     */
    removeSsh() {
        return __awaiter(this, void 0, void 0, function* () {
-            var _a;
+            var _a, _b;
            // SSH key
            const keyPath = this.sshKeyPath || stateHelper.SshKeyPath;
            if (keyPath) {
                try {
+                    core.info(`Removing SSH key '${keyPath}'`);
                    yield io.rmRF(keyPath);
                }
                catch (err) {
@@ -399,37 +472,136 @@ class GitAuthHelper {
            const knownHostsPath = this.sshKnownHostsPath || stateHelper.SshKnownHostsPath;
            if (knownHostsPath) {
                try {
+                    core.info(`Removing SSH known hosts '${knownHostsPath}'`);
                    yield io.rmRF(knownHostsPath);
                }
-                catch (_b) {
-                    // Intentionally empty
+                catch (err) {
+                    core.debug(`${(_b = err === null || err === void 0 ? void 0 : err.message) !== null && _b !== void 0 ? _b : err}`);
+                    core.warning(`Failed to remove SSH known hosts '${knownHostsPath}'`);
                }
            }
            // SSH command
+            core.info('Removing SSH command configuration');
            yield this.removeGitConfig(SSH_COMMAND_KEY);
+            yield this.removeSubmoduleGitConfig(SSH_COMMAND_KEY);
        });
    }
+    /**
+     * Removes token-based authentication by cleaning up HTTP headers,
+     * includeIf entries, and credentials config files.
+     */
    removeToken() {
        return __awaiter(this, void 0, void 0, function* () {
-            // HTTP extra header
+            var _a;
+            // Remove HTTP extra header
+            core.info('Removing HTTP extra header');
            yield this.removeGitConfig(this.tokenConfigKey);
-        });
-    }
-    removeGitConfig(configKey_1) {
-        return __awaiter(this, arguments, void 0, function* (configKey, submoduleOnly = false) {
-            if (!submoduleOnly) {
-                if ((yield this.git.configExists(configKey)) &&
-                    !(yield this.git.tryConfigUnset(configKey))) {
-                    // Load the config contents
-                    core.warning(`Failed to remove '${configKey}' from the git config`);
+            yield this.removeSubmoduleGitConfig(this.tokenConfigKey);
+            // Collect credentials config paths that need to be removed
+            const credentialsPaths = new Set();
+            // Remove includeIf entries that point to git-credentials-*.config files
+            core.info('Removing includeIf entries pointing to credentials config files');
+            const mainCredentialsPaths = yield this.removeIncludeIfCredentials();
+            mainCredentialsPaths.forEach(path => credentialsPaths.add(path));
+            // Remove submodule includeIf entries that point to git-credentials-*.config files
+            const submoduleConfigPaths = yield this.git.getSubmoduleConfigPaths(true);
+            for (const configPath of submoduleConfigPaths) {
+                const submoduleCredentialsPaths = yield this.removeIncludeIfCredentials(configPath);
+                submoduleCredentialsPaths.forEach(path => credentialsPaths.add(path));
+            }
+            // Remove credentials config files
+            for (const credentialsPath of credentialsPaths) {
+                // Only remove credentials config files if they are under RUNNER_TEMP
+                const runnerTemp = process.env['RUNNER_TEMP'];
+                assert.ok(runnerTemp, 'RUNNER_TEMP is not defined');
+                if (credentialsPath.startsWith(runnerTemp)) {
+                    try {
+                        core.info(`Removing credentials config '${credentialsPath}'`);
+                        yield io.rmRF(credentialsPath);
+                    }
+                    catch (err) {
+                        core.debug(`${(_a = err === null || err === void 0 ? void 0 : err.message) !== null && _a !== void 0 ? _a : err}`);
+                        core.warning(`Failed to remove credentials config '${credentialsPath}'`);
+                    }
+                }
+                else {
+                    core.debug(`Skipping removal of credentials config '${credentialsPath}' - not under RUNNER_TEMP`);
                }
            }
+        });
+    }
+    /**
+     * Removes a git config key from the local repository config.
+     * @param configKey The git config key to remove
+     */
+    removeGitConfig(configKey) {
+        return __awaiter(this, void 0, void 0, function* () {
+            if ((yield this.git.configExists(configKey)) &&
+                !(yield this.git.tryConfigUnset(configKey))) {
+                // Load the config contents
+                core.warning(`Failed to remove '${configKey}' from the git config`);
+            }
+        });
+    }
+    /**
+     * Removes a git config key from all submodule configs.
+     * @param configKey The git config key to remove
+     */
+    removeSubmoduleGitConfig(configKey) {
+        return __awaiter(this, void 0, void 0, function* () {
            const pattern = regexpHelper.escape(configKey);
            yield this.git.submoduleForeach(
-            // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
+            // Wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline.
            `sh -c "git config --local --name-only --get-regexp '${pattern}' && git config --local --unset-all '${configKey}' || :"`, true);
        });
    }
+    /**
+     * Removes includeIf entries that point to git-credentials-*.config files.
+     * @param configPath Optional path to a specific git config file to operate on
+     * @returns Array of unique credentials config file paths that were found and removed
+     */
+    removeIncludeIfCredentials(configPath) {
+        return __awaiter(this, void 0, void 0, function* () {
+            const credentialsPaths = new Set();
+            try {
+                // Get all includeIf.gitdir keys
+                const keys = yield this.git.tryGetConfigKeys('^includeIf\\.gitdir:', false, // globalConfig?
+                configPath);
+                for (const key of keys) {
+                    // Get all values for this key
+                    const values = yield this.git.tryGetConfigValues(key, false, // globalConfig?
+                    configPath);
+                    if (values.length > 0) {
+                        // Remove only values that match git-credentials-<uuid>.config pattern
+                        for (const value of values) {
+                            if (this.testCredentialsConfigPath(value)) {
+                                credentialsPaths.add(value);
+                                yield this.git.tryConfigUnsetValue(key, value, false, configPath);
+                            }
+                        }
+                    }
+                }
+            }
+            catch (err) {
+                // Ignore errors - this is cleanup code
+                if (configPath) {
+                    core.debug(`Error during includeIf cleanup for ${configPath}: ${err}`);
+                }
+                else {
+                    core.debug(`Error during includeIf cleanup: ${err}`);
+                }
+            }
+            return Array.from(credentialsPaths);
+        });
+    }
+    /**
+     * Tests if a path matches the git-credentials-*.config pattern.
+     * @param path The path to test
+     * @returns True if the path matches the credentials config pattern
+     */
+    testCredentialsConfigPath(path) {
+        return /git-credentials-[0-9a-f-]+\.config$/i.test(path);
+    }
 }


@@ -481,7 +653,6 @@ const fs = __importStar(__nccwpck_require__(7147));
 const fshelper = __importStar(__nccwpck_require__(7219));
 const io = __importStar(__nccwpck_require__(7436));
 const path = __importStar(__nccwpck_require__(1017));
-const refHelper = __importStar(__nccwpck_require__(8601));
 const regexpHelper = __importStar(__nccwpck_require__(3120));
 const retryHelper = __importStar(__nccwpck_require__(2155));
 const git_version_1 = __nccwpck_require__(3142);
@@ -627,9 +798,15 @@ class GitCommandManager {
            yield this.execGit(args);
        });
    }
-    config(configKey, configValue, globalConfig, add) {
+    config(configKey, configValue, globalConfig, add, configFile) {
        return __awaiter(this, void 0, void 0, function* () {
-            const args = ['config', globalConfig ? '--global' : '--local'];
+            const args = ['config'];
+            if (configFile) {
+                args.push('--file', configFile);
+            }
+            else {
+                args.push(globalConfig ? '--global' : '--local');
+            }
            if (add) {
                args.push('--add');
            }
@@ -653,9 +830,9 @@ class GitCommandManager {
    fetch(refSpec, options) {
        return __awaiter(this, void 0, void 0, function* () {
            const args = ['-c', 'protocol.version=2', 'fetch'];
-            if (!refSpec.some(x => x === refHelper.tagsRefSpec) && !options.fetchTags) {
-                args.push('--no-tags');
-            }
+            // Always use --no-tags for explicit control over tag fetching
+            // Tags are fetched explicitly via refspec when needed
+            args.push('--no-tags');
            args.push('--prune', '--no-recurse-submodules');
            if (options.showProgress) {
                args.push('--progress');
@@ -706,12 +883,27 @@ class GitCommandManager {
            throw new Error('Unexpected output when retrieving default branch');
        });
    }
+    getSubmoduleConfigPaths(recursive) {
+        return __awaiter(this, void 0, void 0, function* () {
+            // Get submodule config file paths.
+            // Use `--show-origin` to get the config file path for each submodule.
+            const output = yield this.submoduleForeach(`git config --local --show-origin --name-only --get-regexp remote.origin.url`, recursive);
+            // Extract config file paths from the output (lines starting with "file:").
+            const configPaths = output.match(/(?<=(^|\n)file:)[^\t]+(?=\tremote\.origin\.url)/g) || [];
+            return configPaths;
+        });
+    }
    getWorkingDirectory() {
        return this.workingDirectory;
    }
-    init() {
+    init(objectFormat) {
        return __awaiter(this, void 0, void 0, function* () {
-            yield this.execGit(['init', this.workingDirectory]);
+            const args = ['init'];
+            if (objectFormat === 'sha256') {
+                args.push('--object-format=sha256');
+            }
+            args.push(this.workingDirectory);
+            yield this.execGit(args);
        });
    }
    isDetached() {
@@ -836,6 +1028,20 @@ class GitCommandManager {
            return output.exitCode === 0;
        });
    }
+    tryConfigUnsetValue(configKey, configValue, globalConfig, configFile) {
+        return __awaiter(this, void 0, void 0, function* () {
+            const args = ['config'];
+            if (configFile) {
+                args.push('--file', configFile);
+            }
+            else {
+                args.push(globalConfig ? '--global' : '--local');
+            }
+            args.push('--unset', configKey, configValue);
+            const output = yield this.execGit(args, true);
+            return output.exitCode === 0;
+        });
+    }
    tryDisableAutomaticGarbageCollection() {
        return __awaiter(this, void 0, void 0, function* () {
            const output = yield this.execGit(['config', '--local', 'gc.auto', '0'], true);
@@ -855,6 +1061,46 @@ class GitCommandManager {
            return stdout;
        });
    }
+    tryGetConfigValues(configKey, globalConfig, configFile) {
+        return __awaiter(this, void 0, void 0, function* () {
+            const args = ['config'];
+            if (configFile) {
+                args.push('--file', configFile);
+            }
+            else {
+                args.push(globalConfig ? '--global' : '--local');
+            }
+            args.push('--get-all', configKey);
+            const output = yield this.execGit(args, true);
+            if (output.exitCode !== 0) {
+                return [];
+            }
+            return output.stdout
+                .trim()
+                .split('\n')
+                .filter(value => value.trim());
+        });
+    }
+    tryGetConfigKeys(pattern, globalConfig, configFile) {
+        return __awaiter(this, void 0, void 0, function* () {
+            const args = ['config'];
+            if (configFile) {
+                args.push('--file', configFile);
+            }
+            else {
+                args.push(globalConfig ? '--global' : '--local');
+            }
+            args.push('--name-only', '--get-regexp', pattern);
+            const output = yield this.execGit(args, true);
+            if (output.exitCode !== 0) {
+                return [];
+            }
+            return output.stdout
+                .trim()
+                .split('\n')
+                .filter(key => key.trim());
+        });
+    }
    tryReset() {
        return __awaiter(this, void 0, void 0, function* () {
            const output = yield this.execGit(['reset', '--hard', 'HEAD'], true);
@@ -964,7 +1210,17 @@ class GitCommandManager {
                }
            }
            // Set the user agent
-            const gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`;
+            let gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`;
+            // Append orchestration ID if set
+            const orchId = process.env['ACTIONS_ORCHESTRATION_ID'];
+            if (orchId) {
+                // Sanitize the orchestration ID to ensure it contains only valid characters
+                // Valid characters: 0-9, a-z, _, -, .
+                const sanitizedId = orchId.replace(/[^a-z0-9_.-]/gi, '_');
+                if (sanitizedId) {
+                    gitHttpUserAgent = `${gitHttpUserAgent} actions_orchestration_id/${sanitizedId}`;
+                }
+            }
            core.debug(`Set git useragent to: ${gitHttpUserAgent}`);
            this.gitEnv['GIT_HTTP_USER_AGENT'] = gitHttpUserAgent;
        });
@@ -1235,8 +1491,17 @@ function getSource(settings) {
            stateHelper.setRepositoryPath(settings.repositoryPath);
            // Initialize the repository
            if (!fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))) {
+                core.startGroup('Determining repository object format');
+                const objectFormatResult = yield githubApiHelper.tryGetRepositoryObjectFormat(settings.authToken, settings.repositoryOwner, settings.repositoryName, settings.githubServerUrl, settings.commit);
+                const objectFormat = objectFormatResult.succeeded
+                    ? objectFormatResult.format
+                    : '';
+                if (objectFormat === 'sha256') {
+                    core.info('Detected SHA-256 repository object format');
+                }
+                core.endGroup();
                core.startGroup('Initializing the repository');
-                yield git.init();
+                yield git.init(objectFormat);
                yield git.remoteAdd('origin', repositoryUrl);
                core.endGroup();
            }
@@ -1287,13 +1552,26 @@ function getSource(settings) {
                if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
                    refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
                    yield git.fetch(refSpec, fetchOptions);
+                    // Verify the ref now matches. For branches, the targeted fetch above brings
+                    // in the specific commit. For tags (fetched by ref), this will fail if
+                    // the tag was moved after the workflow was triggered.
+                    if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                        throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                            `The ref may have been updated after the workflow was triggered.`);
+                    }
                }
            }
            else {
                fetchOptions.fetchDepth = settings.fetchDepth;
-                fetchOptions.fetchTags = settings.fetchTags;
-                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit);
+                const refSpec = refHelper.getRefSpec(settings.ref, settings.commit, settings.fetchTags);
                yield git.fetch(refSpec, fetchOptions);
+                // For tags, verify the ref still points to the expected commit.
+                // Tags are fetched by ref (not commit), so if a tag was moved after the
+                // workflow was triggered, we would silently check out the wrong commit.
+                if (!(yield refHelper.testRef(git, settings.ref, settings.commit))) {
+                    throw new Error(`The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+                        `The ref may have been updated after the workflow was triggered.`);
+                }
            }
            core.endGroup();
            // Checkout info
@@ -1546,6 +1824,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.downloadRepository = downloadRepository;
 exports.getDefaultBranch = getDefaultBranch;
+exports.tryGetRepositoryObjectFormat = tryGetRepositoryObjectFormat;
 const assert = __importStar(__nccwpck_require__(9491));
 const core = __importStar(__nccwpck_require__(2186));
 const fs = __importStar(__nccwpck_require__(7147));
@@ -1647,6 +1926,40 @@ function getDefaultBranch(authToken, owner, repo, baseUrl) {
        }));
    });
 }
+function tryGetRepositoryObjectFormat(authToken, owner, repo, baseUrl, commit) {
+    return __awaiter(this, void 0, void 0, function* () {
+        var _a;
+        const commitFormat = getObjectFormat(commit);
+        if (commitFormat) {
+            return { format: commitFormat, succeeded: true };
+        }
+        try {
+            const octokit = github.getOctokit(authToken, {
+                baseUrl: (0, url_helper_1.getServerApiUrl)(baseUrl)
+            });
+            const response = yield octokit.request('GET /repos/{owner}/{repo}/hash-algorithm', { owner, repo });
+            const hashAlgorithm = response.data.hash_algorithm;
+            if (hashAlgorithm === 'sha256' || hashAlgorithm === 'sha1') {
+                return { format: hashAlgorithm, succeeded: true };
+            }
+            core.debug('Unable to determine repository object format from hash-algorithm endpoint');
+            return { format: '', succeeded: false };
+        }
+        catch (err) {
+            core.debug(`Unable to determine repository object format from hash-algorithm endpoint: ${(_a = err === null || err === void 0 ? void 0 : err.message) !== null && _a !== void 0 ? _a : err}`);
+            return { format: '', succeeded: false };
+        }
+    });
+}
+function getObjectFormat(sha) {
+    if (/^[0-9a-fA-F]{64}$/.test(sha || '')) {
+        return 'sha256';
+    }
+    if (/^[0-9a-fA-F]{40}$/.test(sha || '')) {
+        return 'sha1';
+    }
+    return '';
+}
 function downloadArchive(authToken, owner, repo, ref, commit, baseUrl) {
    return __awaiter(this, void 0, void 0, function* () {
        const octokit = github.getOctokit(authToken, {
@@ -1710,6 +2023,7 @@ const core = __importStar(__nccwpck_require__(2186));
 const fsHelper = __importStar(__nccwpck_require__(7219));
 const github = __importStar(__nccwpck_require__(5438));
 const path = __importStar(__nccwpck_require__(1017));
+const unsafePrCheckoutHelper = __importStar(__nccwpck_require__(843));
 const workflowContextHelper = __importStar(__nccwpck_require__(9568));
 function getInputs() {
    return __awaiter(this, void 0, void 0, function* () {
@@ -1757,7 +2071,7 @@ function getInputs() {
            }
        }
        // SHA?
-        else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
+        else if (result.ref.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) {
            result.commit = result.ref;
            result.ref = '';
        }
@@ -1831,6 +2145,17 @@ function getInputs() {
        // Determine the GitHub URL that the repository is being hosted from
        result.githubServerUrl = core.getInput('github-server-url');
        core.debug(`GitHub Host URL = ${result.githubServerUrl}`);
+        // Allow unsafe PR checkout (opt-in for pull_request_target / workflow_run fork PRs)
+        result.allowUnsafePrCheckout =
+            (core.getInput('allow-unsafe-pr-checkout') || 'false').toUpperCase() ===
+                'TRUE';
+        core.debug(`allow unsafe PR checkout = ${result.allowUnsafePrCheckout}`);
+        unsafePrCheckoutHelper.assertSafePrCheckout({
+            qualifiedRepository,
+            ref: result.ref,
+            commit: result.commit,
+            allowUnsafePrCheckout: result.allowUnsafePrCheckout
+        });
        return result;
    });
 }
@@ -1971,6 +2296,7 @@ exports.getRefSpecForAllHistory = getRefSpecForAllHistory;
 exports.getRefSpec = getRefSpec;
 exports.testRef = testRef;
 exports.checkCommitInfo = checkCommitInfo;
+exports.fromPayload = fromPayload;
 const core = __importStar(__nccwpck_require__(2186));
 const github = __importStar(__nccwpck_require__(5438));
 const url_helper_1 = __nccwpck_require__(9437);
@@ -2032,53 +2358,67 @@ function getRefSpecForAllHistory(ref, commit) {
    }
    return result;
 }
-function getRefSpec(ref, commit) {
+function getRefSpec(ref, commit, fetchTags) {
    if (!ref && !commit) {
        throw new Error('Args ref and commit cannot both be empty');
    }
    const upperRef = (ref || '').toUpperCase();
+    const result = [];
+    // When fetchTags is true, always include the tags refspec
+    if (fetchTags) {
+        result.push(exports.tagsRefSpec);
+    }
    // SHA
    if (commit) {
        // refs/heads
        if (upperRef.startsWith('REFS/HEADS/')) {
            const branch = ref.substring('refs/heads/'.length);
-            return [`+${commit}:refs/remotes/origin/${branch}`];
+            result.push(`+${commit}:refs/remotes/origin/${branch}`);
        }
        // refs/pull/
        else if (upperRef.startsWith('REFS/PULL/')) {
            const branch = ref.substring('refs/pull/'.length);
-            return [`+${commit}:refs/remotes/pull/${branch}`];
+            result.push(`+${commit}:refs/remotes/pull/${branch}`);
        }
        // refs/tags/
        else if (upperRef.startsWith('REFS/TAGS/')) {
-            return [`+${commit}:${ref}`];
+            if (!fetchTags) {
+                result.push(`+${ref}:${ref}`);
+            }
        }
        // Otherwise no destination ref
        else {
-            return [commit];
+            result.push(commit);
        }
    }
    // Unqualified ref, check for a matching branch or tag
    else if (!upperRef.startsWith('REFS/')) {
-        return [
-            `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
-            `+refs/tags/${ref}*:refs/tags/${ref}*`
-        ];
+        result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`);
+        if (!fetchTags) {
+            result.push(`+refs/tags/${ref}*:refs/tags/${ref}*`);
+        }
    }
    // refs/heads/
    else if (upperRef.startsWith('REFS/HEADS/')) {
        const branch = ref.substring('refs/heads/'.length);
-        return [`+${ref}:refs/remotes/origin/${branch}`];
+        result.push(`+${ref}:refs/remotes/origin/${branch}`);
    }
    // refs/pull/
    else if (upperRef.startsWith('REFS/PULL/')) {
        const branch = ref.substring('refs/pull/'.length);
-        return [`+${ref}:refs/remotes/pull/${branch}`];
+        result.push(`+${ref}:refs/remotes/pull/${branch}`);
    }
    // refs/tags/
-    else {
-        return [`+${ref}:${ref}`];
+    else if (upperRef.startsWith('REFS/TAGS/')) {
+        if (!fetchTags) {
+            result.push(`+${ref}:${ref}`);
+        }
    }
+    // Other refs
+    else {
+        result.push(`+${ref}:${ref}`);
+    }
+    return result;
 }
 /**
 * Tests whether the initial fetch created the ref at the expected commit
@@ -2114,7 +2454,9 @@ function testRef(git, ref, commit) {
        // refs/tags/
        else if (upperRef.startsWith('REFS/TAGS/')) {
            const tagName = ref.substring('refs/tags/'.length);
-            return ((yield git.tagExists(tagName)) && commit === (yield git.revParse(ref)));
+            // Use ^{commit} to dereference annotated tags to their underlying commit
+            return ((yield git.tagExists(tagName)) &&
+                commit === (yield git.revParse(`${ref}^{commit}`)));
        }
        // Unexpected
        else {
@@ -2164,7 +2506,7 @@ function checkCommitInfo(token, commitInfo, repositoryOwner, repositoryName, ref
                return;
            }
            // Extract details from message
-            const match = commitInfo.match(/Merge ([0-9a-f]{40}) into ([0-9a-f]{40})/);
+            const match = commitInfo.match(/Merge ([0-9a-f]{40}|[0-9a-f]{64}) into ([0-9a-f]{40}|[0-9a-f]{64})/);
            if (!match) {
                core.debug('Unexpected message format');
                return;
@@ -2403,6 +2745,97 @@ if (!exports.IsPost) {
 }


+/***/ }),
+
+/***/ 843:
+/***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
+
+"use strict";
+
+var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
+}) : (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    o[k2] = m[k];
+}));
+var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
+    Object.defineProperty(o, "default", { enumerable: true, value: v });
+}) : function(o, v) {
+    o["default"] = v;
+});
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
+    __setModuleDefault(result, mod);
+    return result;
+};
+Object.defineProperty(exports, "__esModule", ({ value: true }));
+exports.assertSafePrCheckout = assertSafePrCheckout;
+const github = __importStar(__nccwpck_require__(5438));
+const ref_helper_1 = __nccwpck_require__(8601);
+const PR_REF_PATTERN = /^refs\/pull\/[0-9]+\/(?:head|merge)$/;
+function assertSafePrCheckout(input) {
+    if (input.allowUnsafePrCheckout) {
+        return;
+    }
+    const eventName = github.context.eventName;
+    if (eventName !== 'pull_request_target' && eventName !== 'workflow_run') {
+        return;
+    }
+    const baseRepoId = (0, ref_helper_1.fromPayload)('repository.id');
+    if (typeof baseRepoId !== 'number') {
+        return;
+    }
+    let prHeadRepoId;
+    const prShas = [];
+    if (eventName === 'pull_request_target') {
+        prHeadRepoId = (0, ref_helper_1.fromPayload)('pull_request.head.repo.id');
+        pushIfSha(prShas, (0, ref_helper_1.fromPayload)('pull_request.head.sha'));
+        pushIfSha(prShas, (0, ref_helper_1.fromPayload)('pull_request.merge_commit_sha'));
+    }
+    else {
+        const wrEvent = (0, ref_helper_1.fromPayload)('workflow_run.event');
+        if (typeof wrEvent !== 'string' || !wrEvent.startsWith('pull_request')) {
+            return;
+        }
+        prHeadRepoId = (0, ref_helper_1.fromPayload)('workflow_run.head_repository.id');
+        pushIfSha(prShas, (0, ref_helper_1.fromPayload)('workflow_run.head_commit.id'));
+    }
+    // (A) Fork PR?
+    if (typeof prHeadRepoId !== 'number' || prHeadRepoId === baseRepoId) {
+        return;
+    }
+    // (B) We cannot check for all fork PR refs so check to see
+    // if the resolved input points to the fork PR sha we have in the payload
+    const baseQualifiedRepository = `${github.context.repo.owner}/${github.context.repo.repo}`;
+    const repositoryDiffersFromBase = input.qualifiedRepository.toLowerCase() !==
+        baseQualifiedRepository.toLowerCase();
+    const refMatchesPullPattern = PR_REF_PATTERN.test(input.ref);
+    const commitMatchesPrHeadSha = !!input.commit && prShas.includes(input.commit.toLowerCase());
+    if (!repositoryDiffersFromBase &&
+        !refMatchesPullPattern &&
+        !commitMatchesPrHeadSha) {
+        return;
+    }
+    throw new Error(`Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
+        `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
+        `cache scope, and runner access. Fetching fork's code in that trusted context is a ` +
+        `"pwn request" supply-chain attack pattern. To opt in after reviewing the risk, set ` +
+        `'allow-unsafe-pr-checkout: true' on the actions/checkout step.`);
+}
+function pushIfSha(target, value) {
+    if (typeof value === 'string' && value.length > 0) {
+        target.push(value.toLowerCase());
+    }
+}
+
+
 /***/ }),

 /***/ 9437:
@@ -43,6 +43,7 @@ class GitAuthHelper {
  private sshKeyPath = ''
  private sshKnownHostsPath = ''
  private temporaryHomePath = ''
+  private credentialsConfigPath = '' // Path to separate credentials config file in RUNNER_TEMP

  constructor(
    gitCommandManager: IGitCommandManager,
@@ -126,16 +127,21 @@ class GitAuthHelper {

  async configureGlobalAuth(): Promise<void> {
    // 'configureTempGlobalConfig' noops if already set, just returns the path
-    const newGitConfigPath = await this.configureTempGlobalConfig()
+    await this.configureTempGlobalConfig()
    try {
      // Configure the token
-      await this.configureToken(newGitConfigPath, true)
+      await this.configureToken(true)

      // Configure HTTPS instead of SSH
      await this.git.tryConfigUnset(this.insteadOfKey, true)
      if (!this.settings.sshKey) {
        for (const insteadOfValue of this.insteadOfValues) {
-          await this.git.config(this.insteadOfKey, insteadOfValue, true, true)
+          await this.git.config(
+            this.insteadOfKey,
+            insteadOfValue,
+            true, // globalConfig?
+            true // add?
+          )
        }
      }
    } catch (err) {
@@ -150,24 +156,60 @@ class GitAuthHelper {

  async configureSubmoduleAuth(): Promise<void> {
    // Remove possible previous HTTPS instead of SSH
-    await this.removeGitConfig(this.insteadOfKey, true)
+    await this.removeSubmoduleGitConfig(this.insteadOfKey)

    if (this.settings.persistCredentials) {
-      // Configure a placeholder value. This approach avoids the credential being captured
-      // by process creation audit events, which are commonly logged. For more information,
-      // refer to https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
-      const output = await this.git.submoduleForeach(
-        // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
-        `sh -c "git config --local '${this.tokenConfigKey}' '${this.tokenPlaceholderConfigValue}' && git config --local --show-origin --name-only --get-regexp remote.origin.url"`,
+      // Get the credentials config file path in RUNNER_TEMP
+      const credentialsConfigPath = this.getCredentialsConfigPath()
+
+      // Container credentials config path
+      const containerCredentialsPath = path.posix.join(
+        '/github/runner_temp',
+        path.basename(credentialsConfigPath)
+      )
+
+      // Get submodule config file paths.
+      const configPaths = await this.git.getSubmoduleConfigPaths(
        this.settings.nestedSubmodules
      )

-      // Replace the placeholder
-      const configPaths: string[] =
-        output.match(/(?<=(^|\n)file:)[^\t]+(?=\tremote\.origin\.url)/g) || []
+      // For each submodule, configure includeIf entries pointing to the shared credentials file.
+      // Configure both host and container paths to support Docker container actions.
      for (const configPath of configPaths) {
-        core.debug(`Replacing token placeholder in '${configPath}'`)
-        await this.replaceTokenPlaceholder(configPath)
+        // Submodule Git directory
+        let submoduleGitDir = path.dirname(configPath) // The config file is at .git/modules/submodule-name/config
+        submoduleGitDir = submoduleGitDir.replace(/\\/g, '/') // Use forward slashes, even on Windows
+
+        // Configure host includeIf
+        await this.git.config(
+          `includeIf.gitdir:${submoduleGitDir}.path`,
+          credentialsConfigPath,
+          false, // globalConfig?
+          false, // add?
+          configPath
+        )
+
+        // Container submodule git directory
+        const githubWorkspace = process.env['GITHUB_WORKSPACE']
+        assert.ok(githubWorkspace, 'GITHUB_WORKSPACE is not defined')
+        let relativeSubmoduleGitDir = path.relative(
+          githubWorkspace,
+          submoduleGitDir
+        )
+        relativeSubmoduleGitDir = relativeSubmoduleGitDir.replace(/\\/g, '/') // Use forward slashes, even on Windows
+        const containerSubmoduleGitDir = path.posix.join(
+          '/github/workspace',
+          relativeSubmoduleGitDir
+        )
+
+        // Configure container includeIf
+        await this.git.config(
+          `includeIf.gitdir:${containerSubmoduleGitDir}.path`,
+          containerCredentialsPath,
+          false, // globalConfig?
+          false, // add?
+          configPath
+        )
      }

      if (this.settings.sshKey) {
@@ -201,6 +243,10 @@ class GitAuthHelper {
    }
  }

+  /**
+   * Configures SSH authentication by writing the SSH key and known hosts,
+   * and setting up the GIT_SSH_COMMAND environment variable.
+   */
  private async configureSsh(): Promise<void> {
    if (!this.settings.sshKey) {
      return
@@ -272,57 +318,127 @@ class GitAuthHelper {
    }
  }

-  private async configureToken(
-    configPath?: string,
-    globalConfig?: boolean
-  ): Promise<void> {
-    // Validate args
-    assert.ok(
-      (configPath && globalConfig) || (!configPath && !globalConfig),
-      'Unexpected configureToken parameter combinations'
-    )
+  /**
+   * Configures token-based authentication by creating a credentials config file
+   * and setting up includeIf entries to reference it.
+   * @param globalConfig Whether to configure global config instead of local
+   */
+  private async configureToken(globalConfig?: boolean): Promise<void> {
+    // Get the credentials config file path in RUNNER_TEMP
+    const credentialsConfigPath = this.getCredentialsConfigPath()

-    // Default config path
-    if (!configPath && !globalConfig) {
-      configPath = path.join(this.git.getWorkingDirectory(), '.git', 'config')
-    }
-
-    // Configure a placeholder value. This approach avoids the credential being captured
-    // by process creation audit events, which are commonly logged. For more information,
-    // refer to https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
+    // Write placeholder to the separate credentials config file using git config.
+    // This approach avoids the credential being captured by process creation audit events,
+    // which are commonly logged. For more information, refer to
+    // https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/component-updates/command-line-process-auditing
    await this.git.config(
      this.tokenConfigKey,
      this.tokenPlaceholderConfigValue,
-      globalConfig
+      false, // globalConfig?
+      false, // add?
+      credentialsConfigPath
    )

-    // Replace the placeholder
-    await this.replaceTokenPlaceholder(configPath || '')
-  }
-
-  private async replaceTokenPlaceholder(configPath: string): Promise<void> {
-    assert.ok(configPath, 'configPath is not defined')
-    let content = (await fs.promises.readFile(configPath)).toString()
+    // Replace the placeholder in the credentials config file
+    let content = (await fs.promises.readFile(credentialsConfigPath)).toString()
    const placeholderIndex = content.indexOf(this.tokenPlaceholderConfigValue)
    if (
      placeholderIndex < 0 ||
      placeholderIndex != content.lastIndexOf(this.tokenPlaceholderConfigValue)
    ) {
-      throw new Error(`Unable to replace auth placeholder in ${configPath}`)
+      throw new Error(
+        `Unable to replace auth placeholder in ${credentialsConfigPath}`
+      )
    }
    assert.ok(this.tokenConfigValue, 'tokenConfigValue is not defined')
    content = content.replace(
      this.tokenPlaceholderConfigValue,
      this.tokenConfigValue
    )
-    await fs.promises.writeFile(configPath, content)
+    await fs.promises.writeFile(credentialsConfigPath, content)
+
+    // Add include or includeIf to reference the credentials config
+    if (globalConfig) {
+      // Global config file is temporary
+      await this.git.config(
+        'include.path',
+        credentialsConfigPath,
+        true // globalConfig?
+      )
+    } else {
+      // Host git directory
+      let gitDir = path.join(this.git.getWorkingDirectory(), '.git')
+      gitDir = gitDir.replace(/\\/g, '/') // Use forward slashes, even on Windows
+
+      // Configure host includeIf
+      const hostIncludeKey = `includeIf.gitdir:${gitDir}.path`
+      await this.git.config(hostIncludeKey, credentialsConfigPath)
+
+      // Configure host includeIf for worktrees
+      const hostWorktreeIncludeKey = `includeIf.gitdir:${gitDir}/worktrees/*.path`
+      await this.git.config(hostWorktreeIncludeKey, credentialsConfigPath)
+
+      // Container git directory
+      const workingDirectory = this.git.getWorkingDirectory()
+      const githubWorkspace = process.env['GITHUB_WORKSPACE']
+      assert.ok(githubWorkspace, 'GITHUB_WORKSPACE is not defined')
+      let relativePath = path.relative(githubWorkspace, workingDirectory)
+      relativePath = relativePath.replace(/\\/g, '/') // Use forward slashes, even on Windows
+      const containerGitDir = path.posix.join(
+        '/github/workspace',
+        relativePath,
+        '.git'
+      )
+
+      // Container credentials config path
+      const containerCredentialsPath = path.posix.join(
+        '/github/runner_temp',
+        path.basename(credentialsConfigPath)
+      )
+
+      // Configure container includeIf
+      const containerIncludeKey = `includeIf.gitdir:${containerGitDir}.path`
+      await this.git.config(containerIncludeKey, containerCredentialsPath)
+
+      // Configure container includeIf for worktrees
+      const containerWorktreeIncludeKey = `includeIf.gitdir:${containerGitDir}/worktrees/*.path`
+      await this.git.config(
+        containerWorktreeIncludeKey,
+        containerCredentialsPath
+      )
+    }
  }

+  /**
+   * Gets or creates the path to the credentials config file in RUNNER_TEMP.
+   * @returns The absolute path to the credentials config file
+   */
+  private getCredentialsConfigPath(): string {
+    if (this.credentialsConfigPath) {
+      return this.credentialsConfigPath
+    }
+
+    const runnerTemp = process.env['RUNNER_TEMP'] || ''
+    assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
+
+    // Create a unique filename for this checkout instance
+    const configFileName = `git-credentials-${uuid()}.config`
+    this.credentialsConfigPath = path.join(runnerTemp, configFileName)
+
+    core.debug(`Credentials config path: ${this.credentialsConfigPath}`)
+    return this.credentialsConfigPath
+  }
+
+  /**
+   * Removes SSH authentication configuration by cleaning up SSH keys,
+   * known hosts files, and SSH command configurations.
+   */
  private async removeSsh(): Promise<void> {
    // SSH key
    const keyPath = this.sshKeyPath || stateHelper.SshKeyPath
    if (keyPath) {
      try {
+        core.info(`Removing SSH key '${keyPath}'`)
        await io.rmRF(keyPath)
      } catch (err) {
        core.debug(`${(err as any)?.message ?? err}`)
@@ -335,40 +451,149 @@ class GitAuthHelper {
      this.sshKnownHostsPath || stateHelper.SshKnownHostsPath
    if (knownHostsPath) {
      try {
+        core.info(`Removing SSH known hosts '${knownHostsPath}'`)
        await io.rmRF(knownHostsPath)
-      } catch {
-        // Intentionally empty
+      } catch (err) {
+        core.debug(`${(err as any)?.message ?? err}`)
+        core.warning(`Failed to remove SSH known hosts '${knownHostsPath}'`)
      }
    }

    // SSH command
+    core.info('Removing SSH command configuration')
    await this.removeGitConfig(SSH_COMMAND_KEY)
+    await this.removeSubmoduleGitConfig(SSH_COMMAND_KEY)
  }

+  /**
+   * Removes token-based authentication by cleaning up HTTP headers,
+   * includeIf entries, and credentials config files.
+   */
  private async removeToken(): Promise<void> {
-    // HTTP extra header
+    // Remove HTTP extra header
+    core.info('Removing HTTP extra header')
    await this.removeGitConfig(this.tokenConfigKey)
-  }
+    await this.removeSubmoduleGitConfig(this.tokenConfigKey)

-  private async removeGitConfig(
-    configKey: string,
-    submoduleOnly: boolean = false
-  ): Promise<void> {
-    if (!submoduleOnly) {
-      if (
-        (await this.git.configExists(configKey)) &&
-        !(await this.git.tryConfigUnset(configKey))
-      ) {
-        // Load the config contents
-        core.warning(`Failed to remove '${configKey}' from the git config`)
-      }
+    // Collect credentials config paths that need to be removed
+    const credentialsPaths = new Set<string>()
+
+    // Remove includeIf entries that point to git-credentials-*.config files
+    core.info('Removing includeIf entries pointing to credentials config files')
+    const mainCredentialsPaths = await this.removeIncludeIfCredentials()
+    mainCredentialsPaths.forEach(path => credentialsPaths.add(path))
+
+    // Remove submodule includeIf entries that point to git-credentials-*.config files
+    const submoduleConfigPaths = await this.git.getSubmoduleConfigPaths(true)
+    for (const configPath of submoduleConfigPaths) {
+      const submoduleCredentialsPaths =
+        await this.removeIncludeIfCredentials(configPath)
+      submoduleCredentialsPaths.forEach(path => credentialsPaths.add(path))
    }

+    // Remove credentials config files
+    for (const credentialsPath of credentialsPaths) {
+      // Only remove credentials config files if they are under RUNNER_TEMP
+      const runnerTemp = process.env['RUNNER_TEMP']
+      assert.ok(runnerTemp, 'RUNNER_TEMP is not defined')
+      if (credentialsPath.startsWith(runnerTemp)) {
+        try {
+          core.info(`Removing credentials config '${credentialsPath}'`)
+          await io.rmRF(credentialsPath)
+        } catch (err) {
+          core.debug(`${(err as any)?.message ?? err}`)
+          core.warning(
+            `Failed to remove credentials config '${credentialsPath}'`
+          )
+        }
+      } else {
+        core.debug(
+          `Skipping removal of credentials config '${credentialsPath}' - not under RUNNER_TEMP`
+        )
+      }
+    }
+  }
+
+  /**
+   * Removes a git config key from the local repository config.
+   * @param configKey The git config key to remove
+   */
+  private async removeGitConfig(configKey: string): Promise<void> {
+    if (
+      (await this.git.configExists(configKey)) &&
+      !(await this.git.tryConfigUnset(configKey))
+    ) {
+      // Load the config contents
+      core.warning(`Failed to remove '${configKey}' from the git config`)
+    }
+  }
+
+  /**
+   * Removes a git config key from all submodule configs.
+   * @param configKey The git config key to remove
+   */
+  private async removeSubmoduleGitConfig(configKey: string): Promise<void> {
    const pattern = regexpHelper.escape(configKey)
    await this.git.submoduleForeach(
-      // wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline
+      // Wrap the pipeline in quotes to make sure it's handled properly by submoduleForeach, rather than just the first part of the pipeline.
      `sh -c "git config --local --name-only --get-regexp '${pattern}' && git config --local --unset-all '${configKey}' || :"`,
      true
    )
  }
+
+  /**
+   * Removes includeIf entries that point to git-credentials-*.config files.
+   * @param configPath Optional path to a specific git config file to operate on
+   * @returns Array of unique credentials config file paths that were found and removed
+   */
+  private async removeIncludeIfCredentials(
+    configPath?: string
+  ): Promise<string[]> {
+    const credentialsPaths = new Set<string>()
+
+    try {
+      // Get all includeIf.gitdir keys
+      const keys = await this.git.tryGetConfigKeys(
+        '^includeIf\\.gitdir:',
+        false, // globalConfig?
+        configPath
+      )
+
+      for (const key of keys) {
+        // Get all values for this key
+        const values = await this.git.tryGetConfigValues(
+          key,
+          false, // globalConfig?
+          configPath
+        )
+        if (values.length > 0) {
+          // Remove only values that match git-credentials-<uuid>.config pattern
+          for (const value of values) {
+            if (this.testCredentialsConfigPath(value)) {
+              credentialsPaths.add(value)
+              await this.git.tryConfigUnsetValue(key, value, false, configPath)
+            }
+          }
+        }
+      }
+    } catch (err) {
+      // Ignore errors - this is cleanup code
+      if (configPath) {
+        core.debug(`Error during includeIf cleanup for ${configPath}: ${err}`)
+      } else {
+        core.debug(`Error during includeIf cleanup: ${err}`)
+      }
+    }
+
+    return Array.from(credentialsPaths)
+  }
+
+  /**
+   * Tests if a path matches the git-credentials-*.config pattern.
+   * @param path The path to test
+   * @returns True if the path matches the credentials config pattern
+   */
+  private testCredentialsConfigPath(path: string): boolean {
+    return /git-credentials-[0-9a-f-]+\.config$/i.test(path)
+  }
 }
@@ -28,7 +28,8 @@ export interface IGitCommandManager {
    configKey: string,
    configValue: string,
    globalConfig?: boolean,
-    add?: boolean
+    add?: boolean,
+    configFile?: string
  ): Promise<void>
  configExists(configKey: string, globalConfig?: boolean): Promise<boolean>
  fetch(
@@ -36,13 +37,13 @@ export interface IGitCommandManager {
    options: {
      filter?: string
      fetchDepth?: number
-      fetchTags?: boolean
      showProgress?: boolean
    }
  ): Promise<void>
  getDefaultBranch(repositoryUrl: string): Promise<string>
+  getSubmoduleConfigPaths(recursive: boolean): Promise<string[]>
  getWorkingDirectory(): string
-  init(): Promise<void>
+  init(objectFormat?: string): Promise<void>
  isDetached(): Promise<boolean>
  lfsFetch(ref: string): Promise<void>
  lfsInstall(): Promise<void>
@@ -59,8 +60,24 @@ export interface IGitCommandManager {
  tagExists(pattern: string): Promise<boolean>
  tryClean(): Promise<boolean>
  tryConfigUnset(configKey: string, globalConfig?: boolean): Promise<boolean>
+  tryConfigUnsetValue(
+    configKey: string,
+    configValue: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<boolean>
  tryDisableAutomaticGarbageCollection(): Promise<boolean>
  tryGetFetchUrl(): Promise<string>
+  tryGetConfigValues(
+    configKey: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<string[]>
+  tryGetConfigKeys(
+    pattern: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<string[]>
  tryReset(): Promise<boolean>
  version(): Promise<GitVersion>
 }
@@ -223,9 +240,15 @@ class GitCommandManager {
    configKey: string,
    configValue: string,
    globalConfig?: boolean,
-    add?: boolean
+    add?: boolean,
+    configFile?: string
  ): Promise<void> {
-    const args: string[] = ['config', globalConfig ? '--global' : '--local']
+    const args: string[] = ['config']
+    if (configFile) {
+      args.push('--file', configFile)
+    } else {
+      args.push(globalConfig ? '--global' : '--local')
+    }
    if (add) {
      args.push('--add')
    }
@@ -256,14 +279,13 @@ class GitCommandManager {
    options: {
      filter?: string
      fetchDepth?: number
-      fetchTags?: boolean
      showProgress?: boolean
    }
  ): Promise<void> {
    const args = ['-c', 'protocol.version=2', 'fetch']
-    if (!refSpec.some(x => x === refHelper.tagsRefSpec) && !options.fetchTags) {
-      args.push('--no-tags')
-    }
+    // Always use --no-tags for explicit control over tag fetching
+    // Tags are fetched explicitly via refspec when needed
+    args.push('--no-tags')

    args.push('--prune', '--no-recurse-submodules')
    if (options.showProgress) {
@@ -323,12 +345,33 @@ class GitCommandManager {
    throw new Error('Unexpected output when retrieving default branch')
  }

+  async getSubmoduleConfigPaths(recursive: boolean): Promise<string[]> {
+    // Get submodule config file paths.
+    // Use `--show-origin` to get the config file path for each submodule.
+    const output = await this.submoduleForeach(
+      `git config --local --show-origin --name-only --get-regexp remote.origin.url`,
+      recursive
+    )
+
+    // Extract config file paths from the output (lines starting with "file:").
+    const configPaths =
+      output.match(/(?<=(^|\n)file:)[^\t]+(?=\tremote\.origin\.url)/g) || []
+
+    return configPaths
+  }
+
  getWorkingDirectory(): string {
    return this.workingDirectory
  }

-  async init(): Promise<void> {
-    await this.execGit(['init', this.workingDirectory])
+  async init(objectFormat?: string): Promise<void> {
+    const args = ['init']
+    if (objectFormat === 'sha256') {
+      args.push('--object-format=sha256')
+    }
+    args.push(this.workingDirectory)
+
+    await this.execGit(args)
  }

  async isDetached(): Promise<boolean> {
@@ -455,6 +498,24 @@ class GitCommandManager {
    return output.exitCode === 0
  }

+  async tryConfigUnsetValue(
+    configKey: string,
+    configValue: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<boolean> {
+    const args = ['config']
+    if (configFile) {
+      args.push('--file', configFile)
+    } else {
+      args.push(globalConfig ? '--global' : '--local')
+    }
+    args.push('--unset', configKey, configValue)
+
+    const output = await this.execGit(args, true)
+    return output.exitCode === 0
+  }
+
  async tryDisableAutomaticGarbageCollection(): Promise<boolean> {
    const output = await this.execGit(
      ['config', '--local', 'gc.auto', '0'],
@@ -481,6 +542,56 @@ class GitCommandManager {
    return stdout
  }

+  async tryGetConfigValues(
+    configKey: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<string[]> {
+    const args = ['config']
+    if (configFile) {
+      args.push('--file', configFile)
+    } else {
+      args.push(globalConfig ? '--global' : '--local')
+    }
+    args.push('--get-all', configKey)
+
+    const output = await this.execGit(args, true)
+
+    if (output.exitCode !== 0) {
+      return []
+    }
+
+    return output.stdout
+      .trim()
+      .split('\n')
+      .filter(value => value.trim())
+  }
+
+  async tryGetConfigKeys(
+    pattern: string,
+    globalConfig?: boolean,
+    configFile?: string
+  ): Promise<string[]> {
+    const args = ['config']
+    if (configFile) {
+      args.push('--file', configFile)
+    } else {
+      args.push(globalConfig ? '--global' : '--local')
+    }
+    args.push('--name-only', '--get-regexp', pattern)
+
+    const output = await this.execGit(args, true)
+
+    if (output.exitCode !== 0) {
+      return []
+    }
+
+    return output.stdout
+      .trim()
+      .split('\n')
+      .filter(key => key.trim())
+  }
+
  async tryReset(): Promise<boolean> {
    const output = await this.execGit(['reset', '--hard', 'HEAD'], true)
    return output.exitCode === 0
@@ -623,7 +734,19 @@ class GitCommandManager {
      }
    }
    // Set the user agent
-    const gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`
+    let gitHttpUserAgent = `git/${this.gitVersion} (github-actions-checkout)`
+
+    // Append orchestration ID if set
+    const orchId = process.env['ACTIONS_ORCHESTRATION_ID']
+    if (orchId) {
+      // Sanitize the orchestration ID to ensure it contains only valid characters
+      // Valid characters: 0-9, a-z, _, -, .
+      const sanitizedId = orchId.replace(/[^a-z0-9_.-]/gi, '_')
+      if (sanitizedId) {
+        gitHttpUserAgent = `${gitHttpUserAgent} actions_orchestration_id/${sanitizedId}`
+      }
+    }
+
    core.debug(`Set git useragent to: ${gitHttpUserAgent}`)
    this.gitEnv['GIT_HTTP_USER_AGENT'] = gitHttpUserAgent
  }
@@ -109,8 +109,25 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
    if (
      !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
    ) {
+      core.startGroup('Determining repository object format')
+      const objectFormatResult =
+        await githubApiHelper.tryGetRepositoryObjectFormat(
+          settings.authToken,
+          settings.repositoryOwner,
+          settings.repositoryName,
+          settings.githubServerUrl,
+          settings.commit
+        )
+      const objectFormat = objectFormatResult.succeeded
+        ? objectFormatResult.format
+        : ''
+      if (objectFormat === 'sha256') {
+        core.info('Detected SHA-256 repository object format')
+      }
+      core.endGroup()
+
      core.startGroup('Initializing the repository')
-      await git.init()
+      await git.init(objectFormat)
      await git.remoteAdd('origin', repositoryUrl)
      core.endGroup()
    }
@@ -159,7 +176,6 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
    const fetchOptions: {
      filter?: string
      fetchDepth?: number
-      fetchTags?: boolean
      showProgress?: boolean
    } = {}

@@ -182,12 +198,35 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
      if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
        refSpec = refHelper.getRefSpec(settings.ref, settings.commit)
        await git.fetch(refSpec, fetchOptions)
+
+        // Verify the ref now matches. For branches, the targeted fetch above brings
+        // in the specific commit. For tags (fetched by ref), this will fail if
+        // the tag was moved after the workflow was triggered.
+        if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
+          throw new Error(
+            `The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+              `The ref may have been updated after the workflow was triggered.`
+          )
+        }
      }
    } else {
      fetchOptions.fetchDepth = settings.fetchDepth
-      fetchOptions.fetchTags = settings.fetchTags
-      const refSpec = refHelper.getRefSpec(settings.ref, settings.commit)
+      const refSpec = refHelper.getRefSpec(
+        settings.ref,
+        settings.commit,
+        settings.fetchTags
+      )
      await git.fetch(refSpec, fetchOptions)
+
+      // For tags, verify the ref still points to the expected commit.
+      // Tags are fetched by ref (not commit), so if a tag was moved after the
+      // workflow was triggered, we would silently check out the wrong commit.
+      if (!(await refHelper.testRef(git, settings.ref, settings.commit))) {
+        throw new Error(
+          `The ref '${settings.ref}' does not point to the expected commit '${settings.commit}'. ` +
+            `The ref may have been updated after the workflow was triggered.`
+        )
+      }
    }
    core.endGroup()

@@ -118,4 +118,10 @@ export interface IGitSourceSettings {
   * User override on the GitHub Server/Host URL that hosts the repository to be cloned
   */
  githubServerUrl: string | undefined
+
+  /**
+   * Opt-in to allow checking out fork pull request code from a workflow
+   * triggered by pull_request_target or workflow_run.
+   */
+  allowUnsafePrCheckout: boolean
 }
@@ -11,6 +11,11 @@ import {getServerApiUrl} from './url-helper'

 const IS_WINDOWS = process.platform === 'win32'

+export interface RepositoryObjectFormatResult {
+  format: string
+  succeeded: boolean
+}
+
 export async function downloadRepository(
  authToken: string,
  owner: string,
@@ -122,6 +127,53 @@ export async function getDefaultBranch(
  })
 }

+export async function tryGetRepositoryObjectFormat(
+  authToken: string,
+  owner: string,
+  repo: string,
+  baseUrl?: string,
+  commit?: string
+): Promise<RepositoryObjectFormatResult> {
+  const commitFormat = getObjectFormat(commit)
+  if (commitFormat) {
+    return {format: commitFormat, succeeded: true}
+  }
+
+  try {
+    const octokit = github.getOctokit(authToken, {
+      baseUrl: getServerApiUrl(baseUrl)
+    })
+    const response = await octokit.request(
+      'GET /repos/{owner}/{repo}/hash-algorithm',
+      {owner, repo}
+    )
+    const hashAlgorithm = response.data.hash_algorithm
+    if (hashAlgorithm === 'sha256' || hashAlgorithm === 'sha1') {
+      return {format: hashAlgorithm, succeeded: true}
+    }
+
+    core.debug(
+      'Unable to determine repository object format from hash-algorithm endpoint'
+    )
+    return {format: '', succeeded: false}
+  } catch (err) {
+    core.debug(
+      `Unable to determine repository object format from hash-algorithm endpoint: ${(err as any)?.message ?? err}`
+    )
+    return {format: '', succeeded: false}
+  }
+}
+
+function getObjectFormat(sha?: string): string {
+  if (/^[0-9a-fA-F]{64}$/.test(sha || '')) {
+    return 'sha256'
+  }
+  if (/^[0-9a-fA-F]{40}$/.test(sha || '')) {
+    return 'sha1'
+  }
+  return ''
+}
+
 async function downloadArchive(
  authToken: string,
  owner: string,
@@ -2,6 +2,7 @@ import * as core from '@actions/core'
 import * as fsHelper from './fs-helper'
 import * as github from '@actions/github'
 import * as path from 'path'
+import * as unsafePrCheckoutHelper from './unsafe-pr-checkout-helper'
 import * as workflowContextHelper from './workflow-context-helper'
 import {IGitSourceSettings} from './git-source-settings'

@@ -71,7 +72,7 @@ export async function getInputs(): Promise<IGitSourceSettings> {
    }
  }
  // SHA?
-  else if (result.ref.match(/^[0-9a-fA-F]{40}$/)) {
+  else if (result.ref.match(/^(?:[0-9a-fA-F]{40}|[0-9a-fA-F]{64})$/)) {
    result.commit = result.ref
    result.ref = ''
  }
@@ -161,5 +162,18 @@ export async function getInputs(): Promise<IGitSourceSettings> {
  result.githubServerUrl = core.getInput('github-server-url')
  core.debug(`GitHub Host URL = ${result.githubServerUrl}`)

+  // Allow unsafe PR checkout (opt-in for pull_request_target / workflow_run fork PRs)
+  result.allowUnsafePrCheckout =
+    (core.getInput('allow-unsafe-pr-checkout') || 'false').toUpperCase() ===
+    'TRUE'
+  core.debug(`allow unsafe PR checkout = ${result.allowUnsafePrCheckout}`)
+
+  unsafePrCheckoutHelper.assertSafePrCheckout({
+    qualifiedRepository,
+    ref: result.ref,
+    commit: result.commit,
+    allowUnsafePrCheckout: result.allowUnsafePrCheckout
+  })
+
  return result
 }
@@ -120,7 +120,7 @@ function updateUsage(
 }

 updateUsage(
-  'actions/checkout@v5',
+  'actions/checkout@v6',
  path.join(__dirname, '..', '..', 'action.yml'),
  path.join(__dirname, '..', '..', 'README.md')
 )
@@ -76,55 +76,75 @@ export function getRefSpecForAllHistory(ref: string, commit: string): string[] {
  return result
 }

-export function getRefSpec(ref: string, commit: string): string[] {
+export function getRefSpec(
+  ref: string,
+  commit: string,
+  fetchTags?: boolean
+): string[] {
  if (!ref && !commit) {
    throw new Error('Args ref and commit cannot both be empty')
  }

  const upperRef = (ref || '').toUpperCase()
+  const result: string[] = []
+
+  // When fetchTags is true, always include the tags refspec
+  if (fetchTags) {
+    result.push(tagsRefSpec)
+  }

  // SHA
  if (commit) {
    // refs/heads
    if (upperRef.startsWith('REFS/HEADS/')) {
      const branch = ref.substring('refs/heads/'.length)
-      return [`+${commit}:refs/remotes/origin/${branch}`]
+      result.push(`+${commit}:refs/remotes/origin/${branch}`)
    }
    // refs/pull/
    else if (upperRef.startsWith('REFS/PULL/')) {
      const branch = ref.substring('refs/pull/'.length)
-      return [`+${commit}:refs/remotes/pull/${branch}`]
+      result.push(`+${commit}:refs/remotes/pull/${branch}`)
    }
    // refs/tags/
    else if (upperRef.startsWith('REFS/TAGS/')) {
-      return [`+${commit}:${ref}`]
+      if (!fetchTags) {
+        result.push(`+${ref}:${ref}`)
+      }
    }
    // Otherwise no destination ref
    else {
-      return [commit]
+      result.push(commit)
    }
  }
  // Unqualified ref, check for a matching branch or tag
  else if (!upperRef.startsWith('REFS/')) {
-    return [
-      `+refs/heads/${ref}*:refs/remotes/origin/${ref}*`,
-      `+refs/tags/${ref}*:refs/tags/${ref}*`
-    ]
+    result.push(`+refs/heads/${ref}*:refs/remotes/origin/${ref}*`)
+    if (!fetchTags) {
+      result.push(`+refs/tags/${ref}*:refs/tags/${ref}*`)
+    }
  }
  // refs/heads/
  else if (upperRef.startsWith('REFS/HEADS/')) {
    const branch = ref.substring('refs/heads/'.length)
-    return [`+${ref}:refs/remotes/origin/${branch}`]
+    result.push(`+${ref}:refs/remotes/origin/${branch}`)
  }
  // refs/pull/
  else if (upperRef.startsWith('REFS/PULL/')) {
    const branch = ref.substring('refs/pull/'.length)
-    return [`+${ref}:refs/remotes/pull/${branch}`]
+    result.push(`+${ref}:refs/remotes/pull/${branch}`)
  }
  // refs/tags/
-  else {
-    return [`+${ref}:${ref}`]
+  else if (upperRef.startsWith('REFS/TAGS/')) {
+    if (!fetchTags) {
+      result.push(`+${ref}:${ref}`)
+    }
  }
+  // Other refs
+  else {
+    result.push(`+${ref}:${ref}`)
+  }
+
+  return result
 }

 /**
@@ -170,8 +190,10 @@ export async function testRef(
  // refs/tags/
  else if (upperRef.startsWith('REFS/TAGS/')) {
    const tagName = ref.substring('refs/tags/'.length)
+    // Use ^{commit} to dereference annotated tags to their underlying commit
    return (
-      (await git.tagExists(tagName)) && commit === (await git.revParse(ref))
+      (await git.tagExists(tagName)) &&
+      commit === (await git.revParse(`${ref}^{commit}`))
    )
  }
  // Unexpected
@@ -236,7 +258,9 @@ export async function checkCommitInfo(
    }

    // Extract details from message
-    const match = commitInfo.match(/Merge ([0-9a-f]{40}) into ([0-9a-f]{40})/)
+    const match = commitInfo.match(
+      /Merge ([0-9a-f]{40}|[0-9a-f]{64}) into ([0-9a-f]{40}|[0-9a-f]{64})/
+    )
    if (!match) {
      core.debug('Unexpected message format')
      return
@@ -268,7 +292,7 @@ export async function checkCommitInfo(
  }
 }

-function fromPayload(path: string): any {
+export function fromPayload(path: string): any {
  return select(github.context.payload, path)
 }

@@ -0,0 +1,80 @@
+import * as github from '@actions/github'
+import {fromPayload} from './ref-helper'
+
+const PR_REF_PATTERN = /^refs\/pull\/[0-9]+\/(?:head|merge)$/
+
+export interface IUnsafePrCheckoutInput {
+  qualifiedRepository: string
+  ref: string
+  commit: string
+  allowUnsafePrCheckout: boolean
+}
+
+export function assertSafePrCheckout(input: IUnsafePrCheckoutInput): void {
+  if (input.allowUnsafePrCheckout) {
+    return
+  }
+
+  const eventName = github.context.eventName
+  if (eventName !== 'pull_request_target' && eventName !== 'workflow_run') {
+    return
+  }
+
+  const baseRepoId = fromPayload('repository.id')
+  if (typeof baseRepoId !== 'number') {
+    return
+  }
+
+  let prHeadRepoId: unknown
+  const prShas: string[] = []
+
+  if (eventName === 'pull_request_target') {
+    prHeadRepoId = fromPayload('pull_request.head.repo.id')
+    pushIfSha(prShas, fromPayload('pull_request.head.sha'))
+    pushIfSha(prShas, fromPayload('pull_request.merge_commit_sha'))
+  } else {
+    const wrEvent = fromPayload('workflow_run.event')
+    if (typeof wrEvent !== 'string' || !wrEvent.startsWith('pull_request')) {
+      return
+    }
+    prHeadRepoId = fromPayload('workflow_run.head_repository.id')
+    pushIfSha(prShas, fromPayload('workflow_run.head_commit.id'))
+  }
+
+  // (A) Fork PR?
+  if (typeof prHeadRepoId !== 'number' || prHeadRepoId === baseRepoId) {
+    return
+  }
+
+  // (B) We cannot check for all fork PR refs so check to see
+  // if the resolved input points to the fork PR sha we have in the payload
+  const baseQualifiedRepository = `${github.context.repo.owner}/${github.context.repo.repo}`
+  const repositoryDiffersFromBase =
+    input.qualifiedRepository.toLowerCase() !==
+    baseQualifiedRepository.toLowerCase()
+  const refMatchesPullPattern = PR_REF_PATTERN.test(input.ref)
+  const commitMatchesPrHeadSha =
+    !!input.commit && prShas.includes(input.commit.toLowerCase())
+
+  if (
+    !repositoryDiffersFromBase &&
+    !refMatchesPullPattern &&
+    !commitMatchesPrHeadSha
+  ) {
+    return
+  }
+
+  throw new Error(
+    `Refusing to check out fork pull request code from a '${eventName}' workflow. ` +
+      `This workflow runs with the base repository's GITHUB_TOKEN, secrets, default-branch ` +
+      `cache scope, and runner access. Fetching fork's code in that trusted context is a ` +
+      `"pwn request" supply-chain attack pattern. To opt in after reviewing the risk, set ` +
+      `'allow-unsafe-pr-checkout: true' on the actions/checkout step.`
+  )
+}
+
+function pushIfSha(target: string[], value: unknown): void {
+  if (typeof value === 'string' && value.length > 0) {
+    target.push(value.toLowerCase())
+  }
+}
Author	SHA1	Message	Date
Aiqiao Yan	b8447332b0	block checking out fork pr for some events	2026-06-12 19:12:01 +00:00
Yashwanth Anantharaju	df4cb1c069	Update changelog for v6.0.3 (#2446 )	2026-06-02 10:31:30 -04:00
Yashwanth Anantharaju	1cce3390c2	Fix checkout init for SHA-256 repositories (#2439 ) * Fix checkout init for SHA-256 repositories * Remove unused object format result field	2026-06-01 11:35:58 -04:00
Yashwanth Anantharaju	900f2210b1	fix: expand merge commit SHA regex and add SHA-256 test cases (#2414 ) * fix: expand merge commit SHA regex and add SHA-256 test cases Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * test: add checkCommitInfo SHA coverage Add checkCommitInfo tests for SHA-1 and SHA-256 merge messages and reject invalid 50-character hex merge heads.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * style: fix Prettier formatting in test and source files Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>	2026-05-04 13:30:55 -04:00
eric sciple	0c366fd6a8	Update changelog (#2357 )	2026-01-09 14:09:42 -06:00
eric sciple	de0fac2e45	Fix tag handling: preserve annotations and explicit fetch-tags (#2356 ) This PR fixes several issues with tag handling in the checkout action: 1. fetch-tags: true now works (fixes #1471) - Tags refspec is now included in getRefSpec() when fetchTags=true - Previously tags were only fetched during a separate fetch that was overwritten by the main fetch 2. Tag checkout preserves annotations (fixes #290) - Tags are fetched via refspec (+refs/tags/:refs/tags/) instead of --tags flag - This fetches the actual tag objects, preserving annotations 3. Tag checkout with fetch-tags: true no longer fails (fixes #1467) - When checking out a tag with fetchTags=true, only the wildcard refspec is used (specific tag refspec is redundant) Changes: - src/ref-helper.ts: getRefSpec() now accepts fetchTags parameter and prepends tags refspec when true - src/git-command-manager.ts: fetch() simplified to always use --no-tags, tags are fetched explicitly via refspec - src/git-source-provider.ts: passes fetchTags to getRefSpec() - Added E2E test for fetch-tags option Related #1471, #1467, #290	2026-01-09 13:42:23 -06:00
Copilot	064fe7f331	Add orchestration_id to git user-agent when ACTIONS_ORCHESTRATION_ID is set (#2355 ) * Initial plan * Add orchestration ID support to git user-agent Co-authored-by: TingluoHuang <1750815+TingluoHuang@users.noreply.github.com> * Apply suggestion from @Copilot Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Improve tests to verify user-agent content and handle empty sanitized IDs Co-authored-by: TingluoHuang <1750815+TingluoHuang@users.noreply.github.com> * Simplify orchestration ID validation to accept any non-empty sanitized value Co-authored-by: TingluoHuang <1750815+TingluoHuang@users.noreply.github.com> * Remove test for orchestration ID with only invalid characters Co-authored-by: TingluoHuang <1750815+TingluoHuang@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: TingluoHuang <1750815+TingluoHuang@users.noreply.github.com> Co-authored-by: Tingluo Huang <tingluohuang@github.com> Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>	2026-01-08 15:07:38 -05:00
eric sciple	8e8c483db8	Clarify v6 README (#2328 )	2025-12-01 20:08:49 -06:00
eric sciple	033fa0dc0b	Add worktree support for persist-credentials includeIf (#2327 )	2025-12-01 19:53:23 -06:00
eric sciple	c2d88d3ecc	Update all references from v5 and v4 to v6 (#2314 ) - Updated README.md examples to reference @v6 - Updated all workflow files to use actions/checkout@v6	2025-11-23 19:32:55 -06:00
eric sciple	1af3b93b68	update readme/changelog for v6 (#2311 )	2025-11-20 10:20:04 -06:00
eric sciple	71cf2267d8	v6-beta (#2298 )	2025-11-03 13:40:10 -06:00
eric sciple	069c695914	Persist creds to a separate file (#2286 )	2025-11-03 13:08:38 -06:00
Salman Chishti	ff7abcd0c3	Update README to include Node.js 24 support details and requirements (#2248 ) * Update README to include Node.js 24 support details and requirements * Update	2025-08-13 13:57:25 +01:00