Pin GitHub Actions to full-length commit SHAs

[Dan Fiedler (danfiedler-msft)]

Summary

This PR pins GitHub Actions to full-length commit SHAs for improved security and reproducibility and adds a 7 day cooldown to Dependabot configuration for GitHub Actions. This work is described in more detail at https://aka.ms/action-pinning.

Why?

Pinning actions to commit SHAs prevents supply-chain attacks where a tag could be moved to point to malicious code. This is a recommended security best practice per the GitHub Actions security hardening guide.

This change mitigates the risk of tag retargeting to malicious code as seen in incidents like the tj-actions/changed-files action compromise or codfish/semantic-release-action compromise and improves the integrity and reproducibility of the CI/CD pipeline.

What changed?

Action pinning: Third-party action references in .github/workflows/ that used mutable tag-based references (e.g., actions/checkout@v4) have been updated to full-length commit SHAs with a version comment (e.g., actions/checkout@<sha> # v4) using the pinact tool. References that were already pinned to a SHA, or that used immutable release tags, were left unchanged.

Dependabot configuration: .github/dependabot.yml has been updated to ensure a github-actions package-ecosystem section is present with a cooldown configuration (default-days: 7). If the file did not exist, it was created. If a github-actions section already existed, only the cooldown block was added or its default-days value was increased to 7 if it was lower. The 7-day cooldown provides a window for the community to detect and report compromised releases before they are automatically proposed as updates, reducing exposure to supply-chain attacks via newly published malicious versions.

Is this safe to merge?

Yes. The pinned SHAs correspond to the same commits that the existing tags pointed to. No behavioral changes in action execution are introduced. You can verify the pinned SHA value using the GitHub REST API (e.g., the commit hash for actions/checkout@v7 can be found in the sha property in the JSON response for GET https://api.github.com/repos/actions/checkout/commits/v7).

Additional Information

For more information, please see https://aka.ms/action-pinning

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[Copilot]

Pull request overview

Pins GitHub Actions used across this repo to full commit SHAs (with version comments) to improve workflow reproducibility and reduce supply-chain risk, and updates Dependabot configuration intended to add a cooldown for GitHub Actions updates.

Changes:

• Replaced tag-based uses: owner/action@vX references with full-length commit SHAs across multiple workflows.
• Pinned action references used by the repo’s composite setup action to full commit SHAs.
• Updated .github/dependabot.yml to include (intended) GitHub Actions cooldown configuration.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
.github/workflows/website-gh-pages.yml	Pins actions/checkout, upload-pages-artifact, and deploy-pages to SHAs for Pages deploy workflow.
.github/workflows/verify-labels.yml	Pins actions/checkout to a SHA.
.github/workflows/sync-labels.yml	Pins actions/checkout to a SHA.
.github/workflows/python-integration.yml	Pins checkout/artifact actions to SHAs for Python integration pipeline.
.github/workflows/preview.yml	Pins checkout and setup-dotnet to SHAs.
.github/workflows/merge-release-in-main.yml	Pins actions/checkout to a SHA.
.github/workflows/external-integration.yml	Pins setup-node, checkout, and pnpm/action-setup to SHAs.
.github/workflows/dependabot-pnpm-install.yml	Pins actions/checkout to a SHA.
.github/workflows/core-ci.yml	Pins checkout, setup-dotnet, and upload-artifact to SHAs across CI jobs.
.github/workflows/copilot-setup-steps.yml	Pins checkout and github/gh-aw setup action to SHAs.
.github/workflows/consistency.yml	Pins checkout and upload-artifact to SHAs.
.github/workflows/commenter.yml	Pins checkout and download-artifact to SHAs.
.github/workflows/codeql.yml	Pins checkout and github/codeql-action/* to SHAs.
.github/workflows/ci.yml	Pins checkout (already pinned paths-filter) and updates version comment.
.github/workflows/ci-emitter-diff-python.yml	Pins checkout and setup-python to SHAs.
.github/workflows/check-agentic-workflows.yml	Pins actions/checkout to a SHA.
.github/dependabot.yml	Adds a new GitHub Actions update entry + cooldown (currently malformed; needs correction).
.github/actions/setup/action.yml	Pins pnpm/action-setup and actions/setup-node to SHAs in composite action.

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