OpenClaw versions older than 2026.3.2 contain an authentication bypass in the /api/channels route. The vulnerability stems from a difference in the canonicalization depth used for the authentication path and the route path, allowing attackers to submit deeply encoded slash variants such as multiple encoded %2f characters. By doing so, the authentication checks for the protected /api/channels endpoints are circumvented, giving attackers unauthorized access to endpoints that should require valid credentials. This weakness is identified as CWE‑288 (Authorization Bypass Through User-Controlled Means).

The affected product is OpenClaw from vendor OpenClaw. Any installation of OpenClaw that is at a release earlier than 2026.3.2 is vulnerable. The canonical data indicates that the product is labelled with the CPE cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*, meaning that it runs on Node.js and is vulnerable prior to the 2026.3.2 release.

The vulnerability has a CVSS score of 8.3, indicating high severity. No EPSS score is currently available, and it is not listed in the CISA KEV catalog. Attackers can exploit the flaw by sending HTTP requests to the /api/channels endpoint with deeply encoded slash characters; the exploit does not require an existing authenticated user and can be performed remotely over the network. The attack vector is inferred from the description and, while not explicitly stated, is likely a network-based HTTP request to the vulnerable path. Given the high score and the inherent ease of crafting encoded paths, the risk of exploitation is high if a system remains on an affected version.