The vulnerability resides in the chat.send endpoint of OpenClaw and allows callers with write-scoped gateway permissions to persist admin‑only verboseLevel session overrides by exploiting the /verbose query parameter. This can bypass the intended access controls and expose sensitive reasoning or tool output that is normally restricted to administrators, effectively granting privilege escalation. The weakness is an authorization error (CWE‑863).

OpenClaw before 2026.3.28 is affected; the product is OpenClaw distributed by OpenClaw. All releases older than 2026.3.28 have this flaw, with no specific sub‑product or module identified beyond the main OpenClaw application.

The CVSS score of 5.3 indicates moderate severity, and the EPSS score of less than 1% suggests a low likelihood of exploitation in the wild. Because the flaw is accessed via the chat.send REST endpoint, the likely attack vector is remote, requiring only a web request that includes the /verbose parameter. The vulnerability does not appear in the CISA KEV catalog, reducing the risk of known active exploitation, but any party with write‑scope gateway privileges can abuse the parameter to elevate privileges and read restricted data.