A critical authentication bypass vulnerability in OpenClaw allows unauthenticated attackers with access to the host loopback interface to observe or interact with the sandbox browser.

This vulnerability is categorized as a missing authentication for a critical function (CWE-306). The sandbox browser entrypoint incorrectly executes x11vnc without requiring authentication for noVNC observer sessions, which permits unauthenticated remote attackers to connect to the exposed port.

The exposure of a VNC interface without authentication presents a significant risk to data confidentiality and integrity. An attacker can remotely view sensitive browser activity or interact with the session to perform unauthorized actions, potentially leading to the compromise of credentials or session data. With a CVSS score of 7.7, this vulnerability is considered High severity due to the potential for total impact on the affected sandbox instance.

Immediate Action: Update OpenClaw to version 2026.2.21 or later to ensure that authentication is properly enforced for noVNC sessions.

Proactive Monitoring: Monitor network traffic for unexpected connection attempts to the noVNC service port and review system logs for unauthorized access patterns.

Compensating Controls: Restrict access to the host loopback interface using local firewall rules to prevent unauthorized users or processes from reaching the exposed VNC port.

Public Exploit Available: Unknown.

Given the high severity of this authentication bypass, administrators must prioritize updating the OpenClaw package to version 2026.2.21 immediately. Failure to patch leaves the sandbox environment exposed to unauthorized observation and interaction, which could result in severe data leakage. Ensure that all deployment pipelines are updated to reference the corrected version to prevent future regressions.