OpenClaw versions prior to 2026.4.2 do not normalize host names that include a trailing dot before localhost in remote CDP discovery responses. This allows an attacker to construct a malicious response that presents the host as "localhost." and is treated as a valid loopback address by the client, thereby bypassing the intended protection against accessing local resources. The result is that authenticated browser control can be redirected to localhost endpoints, potentially exposing browser state or facilitating local attacks. This weakness is categorized as a control flow compromise (CWE‑639).

Any deployment of OpenClaw that runs a version older than 2026.4.2 is affected. The vulnerability applies to the core OpenClaw component used for CDP discovery in node.js environments.

The CVSS score of 6.9 indicates moderate severity. No EPSS score is available and the issue is not listed in CISA’s KEV catalog, suggesting limited known exploitation. Exploitation requires an attacker to influence the CDP discovery traffic seen by the client, such as by providing a crafted response over a network path to the victim. The attack is therefore remote in nature and relies on the ability to inject a discovery response that contains a trailing‑dot localhost host. Given the moderate score and the potential to redirect browser traffic to local services, prompt remediation is advisable.