Comprehensive CI/CD security hardening pass over all 33 workflows.
Action pinning
- Every `uses:` is now pinned to a 40-char commit SHA with a `# vX.Y.Z`
comment alongside (167 occurrences resolved). Tag-style refs like `@v4`
are mutable and have been used in past supply-chain attacks (e.g.
tj-actions/changed-files in March 2025) to repoint widely-used actions
to malicious commits.
- Removed redundant `version: "10.13.1"` hardcodes from `pnpm/action-setup`
call sites so the action inherits from package.json `packageManager`
(one source of truth).
Automated maintenance
- Added `.github/dependabot.yml` for the `github-actions` ecosystem so
SHA pins stay current. Without this, pins go stale fast and new
upstream advisories never reach us. Minor/patch bumps are grouped;
major bumps stay separate so they get a real review.
Static analysis
- Added `.github/zizmor.yml` configuration and
`.github/workflows/security_zizmor.yml` (blocking on PR, runs on push
to main, weekly schedule for advisory drift). zizmor catches the
well-known classes of Actions footguns: template injection from
untrusted input, dangerous triggers, unpinned uses, excessive token
scopes, secret exfil patterns.
- All 28 high-severity and 54 medium-severity findings from the baseline
scan are remediated. Each suppression in zizmor.yml carries a
per-finding justification comment so future maintainers can audit the
trust assumption.
Workflow hardening (from zizmor + manual audit)
- Added `persist-credentials: false` to every `actions/checkout` except
the 7 workflows that legitimately push back to the repo via the
workflow token (release tagging, auto-formatting, docs-sync, registry
updates). Each retained credential persistence carries a
`persist-credentials required: ...` comment explaining the call site.
- Routed every attacker-controllable expansion (`github.head_ref`,
`github.event.pull_request.head.repo.full_name`, `inputs.*`,
step outputs) through `env:` and referenced as quoted shell variables.
Eliminates 17 template-injection vectors in fork-PR-reachable
workflows.
- Added per-job `permissions:` blocks across 14 workflows; demoted
broad workflow-level `id-token: write` to the specific Depot-runner
jobs that need it; narrowed `pull-requests: write` /
`actions: write` to the jobs that actually call those APIs.
Audit-driven fixes
- `publish-release.yml` build job: dropped `token:` and added
`persist-credentials: false`. The subsequent `Upload workspace` step
was packing `.git/config` (with the persisted GITHUB_TOKEN) into a
1-day-retention artifact downloadable by anyone with `actions:read`.
- `auto_merge_showcases.yml`: team-membership check now authorizes on
the PR AUTHOR (`pull_request.user.login`), never `context.actor` —
the actor is whoever triggered the latest event, so a team member
synchronizing or reopening an outsider's PR would otherwise
green-light auto-merge of code they didn't author.
- `static_quality.yml`: pinned ruff to a specific version so a
compromised release can't land on the next PR run with the
persisted-credentials write token in the format job.
- `showcase_capture-previews.yml`: switched the args-string construction
to a bash array so a slug or demo value containing whitespace or shell
metacharacters stays a single argument rather than being re-tokenized
by the shell.
Move untrusted PR event data (title, head ref, base ref, SHAs) from
inline ${{ }} interpolation in shell run: blocks to env: blocks,
referencing them as shell variables instead. This prevents arbitrary
code execution via crafted PR titles or branch names.
Affected workflows:
- test_smoke-starter.yml: PR title, user login, head SHA
- publish-release.yml: PR head ref (branch name)
- static_quality.yml: PR base ref, base SHA, head SHA
The failure-alert Slack step crashed every scheduled run with
'Invalid input! Failed to parse contents of the provided payload file'.
Two compounding causes: slackapi/slack-github-action@v2.1.0 rejects
payload files without a .json/.yaml/.yml extension (mktemp produces
extensionless files), and 'jq -n --rawfile' under 'set -e' can abort
on edge-case summary input, leaving an empty/missing payload.
Switch to the inline 'payload:' + toJSON(format(...)) pattern already
used in test_smoke-starter-deployed.yml (PR #4068) and
showcase_validate.yml. Summary text is sanitized into $GITHUB_ENV via
heredoc (handles embedded =, quotes, newlines), then JSON-encoded by
toJSON at template-eval time — no intermediate file, no jq crash path,
genuine outages surface in #oss-alerts instead of being silently
suppressed by a broken notifier.
test_smoke-starter-deployed.yml recovery path (/tmp/...-recovery.json,
jq --arg) and showcase_docs-sync.yml (static slack-payloads/*.json)
use safe patterns already — left unchanged.
dependabot[bot]