# Review by Staff Security Engineer (Round 4)

All 55 verify-specific tests pass. The existing review artifact is comprehensive and current. Here is my assessment:

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VERDICT: approve

FINDINGS:
- [src/colonyos/orchestrator.py]: Verify agent `allowed_tools` correctly restricted to `["Read", "Bash", "Glob", "Grep"]` at runtime — defense-in-depth with instruction-level guidance in `verify.md`
- [src/colonyos/orchestrator.py]: `_verify_detected_failures()` implements structured sentinel parsing (primary) with safe regex fallback — 16 unit tests cover edge cases including the critical `"0 failed"` false-positive scenario
- [src/colonyos/orchestrator.py]: Dual budget guards (before verify AND before fix) prevent runaway cost — fail-safe on exhaustion
- [src/colonyos/orchestrator.py]: Hard-block delivery via `_fail_run_log()` + `return log` when `verify_passed` is False — core invariant "never open a broken PR" is enforced with 3 integration tests
- [src/colonyos/orchestrator.py]: `Phase.FIX` reuse for verify-fix inherits `_SAFETY_CRITICAL_PHASES` membership automatically — net positive for security
- [src/colonyos/instructions/verify_fix.md]: Raw `{test_failure_output}` interpolated into system prompt without sanitization — accepted risk, consistent with existing threat model (user's own repo content)
- [src/colonyos/config.py]: `_parse_verify_config()` validates `max_fix_attempts >= 1` — prevents misconfiguration that could bypass the fix loop
- [src/colonyos/config.py]: `Phase.VERIFY` correctly excluded from `_SAFETY_CRITICAL_PHASES` — allows haiku assignment without warning, confirmed by test

SYNTHESIS:
This implementation is security-sound across all critical boundaries. The core invariant — never open a PR you know is broken — is enforced through multiple layers: runtime tool restriction on the verify agent (not just instruction text), structured sentinel parsing with 16 edge-case tests, dual budget guards, and hard-block delivery via `_fail_run_log()`. The two-agent separation preserves clean audit boundaries between observation (verify, read-only) and mutation (fix, write-enabled), producing separate `PhaseResult` entries for post-incident forensics. All accepted risks (fail-open on ambiguous output, unsanitized test output in fix prompt, `Phase.FIX` reuse) are narrow, documented, and consistent with the existing threat model. All 55 verify-specific tests pass with zero regressions. Ship it.
