OpenClaw's TOCTOU symlink race in writeFileWithinRoot could create or truncate files outside root boundaries
Date: 2026-03
Affected: npm/openclaw
Attack vector: path-traversal
Category: vulnerability-disclosure
Severity: High
CWE: CWE-367
CWE-59

### Summary A symlink-retarget TOCTOU race in `writeFileWithinRoot` could point an attacker-controlled path alias outside the configured root between resolution and write operations. ### Impact Affected versions could cause out-of-root write side effects (including file creation or truncation) before final boundary validation. ### Fix Root-scoped write flow now opens existing files without pre-truncation, creates missing files with exclusive create semantics, truncates only after post-open identity/boundary checks, and removes out-of-root artifacts when a race is detected. ### Affected and Patched Versions - Affected: `<= 2026.2.26` - Patched: `2026.3.1`


Mitigations:

Architectural layers (MAESTRO):