CVE-2026-41393: OpenClaw Information Disclosure Flaw

CVE-2026-41393 Overview

CVE-2026-41393 is a DNS Authority Acceptance vulnerability affecting OpenClaw versions prior to 2026.3.31. The vulnerability exists in OpenClaw's wide-area discovery mechanism, which improperly validates DNS authority sources. Attackers positioned on the same tailnet with access to a CA-trusted endpoint can manipulate DNS steering to exfiltrate operator credentials.

This vulnerability is classified under CWE-346 (Origin Validation Error), indicating that the software fails to properly verify the origin or source of data, allowing malicious peers to be accepted as legitimate DNS authorities.

Critical Impact

Attackers on the same tailnet can exploit the wide-area discovery flaw to redirect DNS queries, enabling credential theft and unauthorized access to sensitive operator information.

Affected Products

• OpenClaw versions prior to 2026.3.31

Discovery Timeline

• 2026-04-28 - CVE-2026-41393 published to NVD
• 2026-04-28 - Last updated in NVD database

Technical Details for CVE-2026-41393

Vulnerability Analysis

The vulnerability stems from improper origin validation in OpenClaw's wide-area discovery feature. When OpenClaw performs peer discovery across a tailnet, it fails to adequately verify which peers should be trusted as DNS authorities. This allows any peer on the same network segment to present itself as a DNS authority, effectively hijacking DNS resolution for the victim.

The attack requires the adversary to be positioned on an adjacent network (same tailnet) and have access to a Certificate Authority (CA) trusted endpoint. Once these preconditions are met, the attacker can manipulate DNS steering—the process by which DNS queries are directed to specific resolvers—to intercept and exfiltrate operator credentials.

Root Cause

The root cause is an Origin Validation Error (CWE-346) in the wide-area discovery component. OpenClaw's peer acceptance logic does not sufficiently validate the authenticity and authorization of peers claiming DNS authority status. The software trusts peer declarations without cryptographic verification of their authority to serve DNS responses, creating an avenue for DNS spoofing within the tailnet boundary.

Attack Vector

The attack vector requires adjacent network access, meaning the attacker must be on the same tailnet as the victim. The exploitation involves several prerequisites that increase attack complexity:

1. Same-Tailnet Position: The attacker must be an authorized peer on the same OpenClaw tailnet
2. CA-Trusted Endpoint Access: Access to a Certificate Authority trusted endpoint is required to establish credibility
3. User Interaction: Some level of user interaction may be required for the attack to succeed

The attacker exploits the wide-area discovery mechanism by advertising themselves as a DNS authority. When victim nodes query DNS through the compromised resolution path, the attacker can steer queries to malicious endpoints designed to harvest credentials. This technique is particularly effective for capturing operator credentials used in administrative functions.

For technical implementation details, refer to the GitHub Security Advisory and the VulnCheck Advisory.

Detection Methods for CVE-2026-41393

Indicators of Compromise

• Unexpected DNS authority advertisements from peers that are not designated DNS servers
• Anomalous DNS query routing patterns within the tailnet
• Credential authentication failures following DNS resolution to suspicious endpoints
• New or unauthorized peers claiming DNS authority status in discovery logs

Detection Strategies

• Monitor OpenClaw discovery logs for peers advertising DNS authority capabilities without authorization
• Implement DNS query logging to identify queries being steered to unexpected resolvers
• Audit tailnet peer lists for unauthorized or suspicious participants
• Configure alerts for credential exfiltration patterns, such as credentials sent to non-standard endpoints

Monitoring Recommendations

• Enable verbose logging for wide-area discovery events in OpenClaw
• Deploy network monitoring to track DNS traffic patterns within the tailnet
• Establish baseline of authorized DNS authorities and alert on deviations
• Implement credential usage monitoring to detect potential exfiltration attempts

How to Mitigate CVE-2026-41393

Immediate Actions Required

• Upgrade OpenClaw to version 2026.3.31 or later immediately
• Audit current tailnet peer list and remove any unauthorized or suspicious peers
• Review DNS authority configurations to ensure only legitimate servers are authorized
• Rotate operator credentials that may have been exposed prior to patching

Patch Information

OpenClaw has released a security update addressing this vulnerability in version 2026.3.31. The fix implements proper origin validation for DNS authority claims during wide-area discovery. The patch can be found in the GitHub commit.

Additional details are available in the GitHub Security Advisory.

Workarounds

• Restrict wide-area discovery functionality until the patch can be applied
• Implement network segmentation to limit peer-to-peer DNS authority claims
• Deploy additional DNS security controls such as DNSSEC where supported
• Configure explicit DNS authority allowlists rather than relying on automatic discovery

Organizations unable to immediately patch should prioritize monitoring and network segmentation as interim protective measures. Consult the VulnCheck Advisory for additional mitigation guidance.