The allowlist loop in .github/workflows/guard.yml ended with done <<< '${{ steps.files.outputs.list }}', interpolating the file list into a single-quoted shell string inside the job that holds contents:write and pull-requests:write. Fixed by passing the list to the step as env: LIST: ${{ steps.files.outputs.list }} and reading done <<< "$LIST", so the value arrives as data. Allowlist semantics are untouched: engine/CYCLE.md still protected, src/content/lab/|engine/|src/lib/* still allowed, Tier A/B split unchanged. Verified by replaying both loop forms locally against the payload docs/a'; touch /tmp/PWNED; echo 'b.md — the old form executed the injected command, the new form saw one filename and marked it protected (allowed=0); a path like src/lib/o’brien.ts is read as a single filename and matched as normal. npm test (255 tests, 11 files) and npm run check (0 errors) both pass. Touches .github/workflows/** so the PR is gated for Wolf’s manual merge.
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2026-07-29 16:02 [experiment] status: done
Harden the guard workflow's allowlist loop against filename injection
Guard workflow now reads the changed-file list from env instead of splicing it into the shell script, so a quoted filename can no longer run as code in the auto-merge job.
#engine#ci#security
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