OpenClaw prior to version 2026.3.31 suffers from a Time‑of‑Check Time‑of‑Use condition within sandbox file operations, allowing an attacker to bypass file descriptor‑based safeguards. By exploiting the check‑then‑act patterns in apply_patch, remove, and mkdir calls, malicious actors can alter or create files between validation and execution, potentially compromising data integrity or enabling privileged code execution within the sandbox. This weakness is classified as CWE‑367.

All OpenClaw installations running any release older than 2026.3.31, across all supported platforms where the Node.js runtime is present. The affected product is OpenClaw:OpenClaw, and the vulnerability is present in the sandbox file handling modules used by the application.

The CVSS score of 4.3 indicates moderate severity, while the EPSS score of <1% points to a low exploitation probability in the near term. Since the vulnerability is not listed in the CISA KEV catalog, there are no confirmed widespread attacks yet. The likely attack vector is local or remote if the sandbox exposes untrusted user input that triggers apply_patch, remove, or mkdir operations – this inference is drawn from the described check‑then‑act pattern. Overall, the risk is moderate, but the potential for privilege escalation within the sandbox warrants timely remediation.