Fix gh-aw-node brace-expansion patch: replace broken npm --prefix overlay with temp-dir copy (GHSA-mh99-v99m-4gvg)

[Copilot]

The published ghcr.io/github/gh-aw-node image contains brace-expansion@5.0.7 (GHSA-mh99-v99m-4gvg, High). The previous Dockerfile fix was silently a no-op.

Root cause

npm install --prefix "$(npm root -g)/npm" reads npm's own package.json at that prefix, which declares @npmcli/docs@^1.0.0 — a private package not on the public registry. The install exits E404 before touching brace-expansion, so the bundled 5.0.7 was never replaced.

Changes

• Dockerfile.safe-outputs-mcp — replace the broken --prefix npm-dir approach with a temp-directory overlay:

  # Before (broken: reads npm's own package.json → E404 for @npmcli/docs)
  && npm install --prefix "$(npm root -g)/npm" --no-save "tar@^7.5.22" "brace-expansion@^5.0.8"
  
  # After (correct: empty temp prefix → installs only what's requested, then overlay)
  && tmpdir=$(mktemp -d) \
  && npm --prefix "$tmpdir" install --no-save "tar@^7.5.22" "brace-expansion@^5.0.8" \
  && npm_modules="$(npm root -g)/npm/node_modules" \
  && cp -rf "$tmpdir/node_modules/brace-expansion/." "$npm_modules/brace-expansion/" \
  && cp -rf "$tmpdir/node_modules/tar/." "$npm_modules/tar/" \
  && rm -rf "$tmpdir"

  With brace-expansion@^5.0.8 now resolving to 5.0.9 (published 2026-07-30), the rebuilt image will have the patched version in npm's bundled node_modules.

• publish-safe-outputs-node.yml — add push trigger scoped to actions/setup/js/Dockerfile.safe-outputs-mcp on main, so the image rebuilds immediately on merge rather than waiting for the next Monday schedule.

Note: After the image is rebuilt, action_pins.json, docker_pin_test.go, and compiled lock files will need a follow-up update with the new image digest.

• Fixes [container-image-scan] test title #49503

[github-actions]

Thanks for tackling the container image vulnerabilities (@copilot-swe-agent)! 🛡️ This PR is off to a good start with a clear description of the issue and remediation goals.

A few things to keep an eye on as you develop this:

• Add test coverage — Once you update the Dockerfile or container build process, consider adding validation tests (e.g., scanning the built image to confirm vulnerability counts are reduced, or verifying license policy compliance).
• Include the actual changes — This is currently a [WIP] draft with no file changes yet. Once you push the Dockerfile updates or build script modifications, the diff will show the specific package version updates and remediation steps.

The PR description is excellent and gives clear context on what needs to be done. Keep it updated as you make progress, and feel free to mark it as ready for review once the implementation is complete and tested.

Generated by ✅ Contribution Check · auto · 46.3 AIC · ⌖ 17.4 AIC · ⊞ 8.8K · ◷

[Copilot]

Pull request overview

Fixes vulnerable bundled npm dependencies in the gh-aw-node image and ensures Dockerfile changes trigger publication.

Changes:

• Installs patched dependencies in a temporary prefix and overlays them into npm.
• Triggers image publication when the Dockerfile changes on main.
• Adds a patch changeset.

Show a summary per file

File	Description
actions/setup/js/Dockerfile.safe-outputs-mcp	Replaces the broken npm dependency patching approach.
.github/workflows/publish-safe-outputs-node.yml	Adds Dockerfile-scoped push publication.
.changeset/patch-refresh-gh-aw-node.md	Documents the security fix and publication trigger.

Review details

Tip

Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

• Files reviewed: 3/3 changed files
• Comments generated: 1
• Review effort level: Balanced

[github-actions]

🎉 This pull request is included in a new release.

Release: v0.84.3