CICD-SEC-3 — Unpinned third-party action

Tag and branch references are mutable. Pin third-party actions to a full commit SHA.

Field	Value
Category	CICD-SEC-3
Severity	MEDIUM
OWASP	CICD-SEC-3: Dependency Chain Abuse
Auto-fix	✓ (what it does)

What the check does

Flags every step whose uses: value references a third-party action by anything other than a 40-character commit SHA:

• owner/repo@v1
• owner/repo@main
• owner/repo/path@release

Local actions (./ or .github/) are ignored.

Why it matters

Tags and branches are mutable. If a maintainer (or an attacker who compromises their account) updates @v1 to point at a malicious commit, every workflow tracking @v1 runs that code on its next invocation — typically with access to repo secrets.

Pinning to a commit SHA freezes the exact bytes you reviewed.

Vulnerable example

- uses: actions/checkout@v4              # ← mutable tag
- uses: some-org/some-action@main        # ← mutable branch

Safe alternative

Pin to a full commit SHA, with the original ref preserved as a comment for human-readable updates:

- uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1

Auto-fix

--fix resolves the tag or branch to a commit SHA by calling the GitHub API, then rewrites the uses: value to owner/repo@<sha> with the original ref preserved as a trailing line comment:

- uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4

The fixer needs network access to api.github.com. If resolution fails (network error, deleted tag, rate limit), the action is left unchanged and a warning is printed to stderr.