CVE-2026-41377: OpenClaw Auth Bypass Vulnerability

CVE-2026-41377 Overview

OpenClaw before version 2026.3.31 contains a fail-open vulnerability in the plugin installation flow where security scan failures do not block installation. This design flaw allows attackers to exploit scan failures to install untrusted plugins when operators proceed despite visible scan warnings, potentially introducing malicious code into the environment.

Critical Impact
Attackers can bypass security scanning mechanisms to install potentially malicious plugins by exploiting the fail-open behavior when security scans fail or encounter errors.

Affected Products

OpenClaw versions prior to 2026.3.31

Discovery Timeline

2026-04-28 - CVE CVE-2026-41377 published to NVD
2026-04-28 - Last updated in NVD database

Technical Details for CVE-2026-41377

Vulnerability Analysis

This vulnerability is classified under CWE-636 (Not Failing Securely / Failing Open), which describes a security design flaw where systems do not properly handle failure conditions in a secure manner. When the security scanning mechanism encounters an error during plugin installation, the system fails to block the installation process, allowing potentially dangerous plugins to be installed despite the scan not completing successfully.

The core issue lies in the installation workflow's error handling logic. Rather than treating scan failures as a blocking condition (fail-closed), the application permits installation to proceed when scans cannot complete their analysis. This creates a window of opportunity for attackers to craft plugins that deliberately cause scan failures, thereby bypassing the security controls entirely.

Root Cause

The root cause is inadequate error handling in the plugin security scanning workflow. The original implementation did not differentiate between a successful scan with no issues, a successful scan with detected issues, and a scan that failed to complete. All non-blocking scan results, including failures, permitted installation to continue. The fix introduces a dangerouslyForceUnsafeInstall flag that must be explicitly set to bypass blocking behavior, ensuring that scan failures are treated as blocking conditions by default.

Attack Vector

This is a network-based attack vector requiring low privileges and passive user interaction. An attacker could exploit this vulnerability by:

Creating a malicious plugin designed to cause security scan timeouts or errors
Distributing the plugin through legitimate channels
When an operator attempts to install the plugin and the scan fails, they may proceed with installation
The malicious plugin is installed without proper security validation

The following code shows the security patch that introduces fail-closed behavior:

typescript

export type InstallSecurityScanResult = {
  blocked?: {
    code?: "security_scan_blocked" | "security_scan_failed";
    reason: string;
  };
};

Source: GitHub Commit Update

The patch adds explicit blocking codes to differentiate between scans that were blocked due to detected issues versus scans that failed entirely, ensuring both conditions prevent installation by default.

Additionally, the fix introduces an explicit override flag for cases where operators intentionally need to bypass the security check:

typescript

    .option(
      "--dangerously-force-unsafe-install",
      "Bypass built-in dangerous-code install blocking (plugin hooks may still block)",
      false,
    )

Source: GitHub Commit Update

Detection Methods for CVE-2026-41377

Indicators of Compromise

Plugin installations that occurred after security scan warnings or errors were displayed
Log entries showing security scan failures followed by successful plugin installations
Presence of plugins installed without corresponding successful scan completion records
Unusual plugin behavior or unexpected network activity from recently installed plugins

Detection Strategies

Review plugin installation logs for patterns of scan failures followed by successful installations
Implement monitoring for the security_scan_failed condition in installation workflows
Audit installed plugins against a known-good baseline to identify unauthorized additions
Monitor for use of --dangerously-force-unsafe-install flag in production environments

Monitoring Recommendations

Enable verbose logging for all plugin installation activities
Configure alerts for any security scan failures during plugin installation attempts
Implement centralized log aggregation to correlate scan failures with installation completions
Establish a review process for any plugins installed with override flags

How to Mitigate CVE-2026-41377

Immediate Actions Required

Upgrade OpenClaw to version 2026.3.31 or later immediately
Audit all plugins installed prior to the upgrade for potential malicious behavior
Review installation logs to identify any plugins installed after scan failures
Remove or quarantine any suspicious plugins pending security review

Patch Information

The vulnerability has been addressed through multiple commits to the OpenClaw repository. The patches introduce fail-closed behavior by default, requiring explicit operator override via the --dangerously-force-unsafe-install flag to proceed when security scans fail. Key patches include:

GitHub Commit 0d7f1e2 - Fail closed on dangerous skill installs
GitHub Commit 44b9936 - Add dangerous unsafe install override
GitHub Commit 7a953a5 - Block install when source scan fails

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

Workarounds

Implement administrative policies prohibiting plugin installations when scan warnings appear
Restrict plugin installation privileges to security-vetted administrators only
Deploy network-level controls to block access to untrusted plugin sources
Manually verify plugin source code and integrity before installation until patching is complete

bash

# Verify OpenClaw version is patched
openclaw --version
# Expected output: 2026.3.31 or higher

# Review installed plugins for audit
openclaw plugins list --verbose