# Review by Staff Security Engineer (Round 1)

## Security Review Complete

**VERDICT: approve** ✅

### Key Security Findings (All Non-Blocking)

The implementation is security-conscious and follows the principle of least privilege throughout:

**What's right:**
- **No `shell=True`** — subprocess uses list args, eliminating shell injection
- **Hardcoded sensitive denylist** (`.env*`, `*credential*`, `*secret*`, `*.pem`, `*.key`) applied *before* user config patterns — can't be overridden
- **`ast.parse()` only, never `eval`/`exec`** — source code is structurally analyzed, never executed
- **Strictly read-only** — no file writes, no git mutations, no side effects
- **No `str.format()` on untrusted content** — avoids the KeyError/config-leakage pattern flagged in prior reviews
- **No persistent caching** — eliminates cache poisoning attack vector
- **30s subprocess timeout** — fail-closed on pathological repos
- **Graceful degradation** on all I/O errors (SyntaxError, UnicodeDecodeError, OSError, TimeoutExpired)

**V1.1 suggestions (non-blocking):**
1. **Expand sensitive denylist** — add `*.p12`, `id_rsa*`, `*token*` for broader coverage
2. **Add max file size check** — `read_text()` has no size bound; a 500MB tracked Python file could cause OOM. Suggest skipping files > 1MB before parsing.

**651/651 tests pass.** All 19 functional requirements implemented. All 7 task groups complete. No secrets, no destructive operations, no commented-out code.

Review saved to `cOS_reviews/reviews/staff_security_engineer/20260331_round1_build_a_repomap_module.md`.