Signetry Admission is a security tool; we hold its own security to a high bar.

Pin the Action to @v1 (moving major tag — always the latest hardened release) or a specific @v0.1.3+ tag.

v0.1.0–v0.1.2 contained a GitHub Actions script-injection sink (action inputs interpolated into a shell body) and a fail-open PR-staging path. These are fixed in v0.1.3. If you pinned an exact old tag, move to @v1.

Do not open a public issue. Use private reporting: https://github.com/Signetry/action/security/advisories/new (or report core issues at https://github.com/Signetry/core/security/advisories/new).

• Grant the workflow the least privilege it needs: contents: read and pull-requests: write (for the verdict comment). Do not pass extra secrets to the action unless you intend the checks to use them.
• Never plumb attacker-controlled text (PR title, branch, issue body) into the mission input; the action passes inputs via environment and validates them, but least privilege is still the right posture.
• Use signing-key: ${{ secrets.SIGNETRY_SIGNING_KEY }} for receipts that verify against your pinned key; without it, receipts use a dev key and are flagged key_ephemeral.
• For fail-closed check isolation set require-sandbox: true.