# Review by Staff Security Engineer (Round 4)

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## Staff Security Engineer Review — Round 4

**VERDICT: approve**

**FINDINGS:**
- [src/colonyos/orchestrator.py:1329-1349]: Secret filter doesn't cover `.npmrc`, `.pypirc`, `*.keystore`, `*.jks`, `*.gpg` — matches existing codebase coverage, extend in follow-up (LOW)
- [src/colonyos/orchestrator.py]: Agent session receives full task descriptions which could theoretically be a prompt injection vector — mitigated by task descriptions originating from the ColonyOS planner, not arbitrary user input (LOW)

**SYNTHESIS:**

This implementation is **approved** from a security perspective. All 5 critical/high/medium findings from my Round 2 and Round 3 reviews have been fixed with test coverage: `git add -A` replaced with selective staging and `_is_secret_like_path()` filter, all subprocess calls have `timeout=30`, per-task audit logging is in place, commit messages are sanitized, and memory/context injection is properly wired per-task.

The sequential-by-default architecture is strictly more secure than parallel worktrees — it eliminates inter-worktree data leakage, removes the merge conflict resolution agent (which had elevated permissions), and produces a clean per-task audit trail via individual commits. Budget isolation per task limits blast radius. The 32 tests include 4 security-specific tests that verify subprocess call arguments, not just return values. The two remaining LOW-severity observations (expanding the secret file filter, theoretical prompt injection via task descriptions) are appropriate follow-ups and do not block shipping.
