## Diamond Recursion Scan (ray) — CLEAN (deeper scan)

**Scan date:** 2026-03-29
**Pattern:** Recursive cycle/dependency check without visited set (CWE-407 diamond recursion, O(2^D))

### Files examined

- `python/ray/dag/dag_node.py:apply_recursive` — uses UUID cache (_CachingFn) for memoization — CLEAN
- `python/ray/dag/dag_node.py:traverse_and_apply` — uses `visited = set()` — CLEAN
- `python/ray/dag/vis_utils.py:_dfs` — delegates to apply_recursive (cached) — CLEAN
- `python/ray/workflow/` — empty (only __init__.py) — CLEAN

### Verdict: CLEAN — no diamond recursion CWE-407 found beyond existing ray-0001
