CVE-2026-42428: Openclaw Auth Bypass Vulnerability

CVE-2026-42428 Overview

OpenClaw versions before 2026.4.8 fail to enforce integrity verification on downloaded plugin archives. This Missing Integrity Check vulnerability (CWE-353) allows attackers to install malicious or tampered plugin packages without detection, compromising the local assistant environment. The vulnerability affects the Node.js implementation of OpenClaw and can be exploited over the network.

Critical Impact
Attackers can intercept and tamper with plugin downloads, injecting malicious code that executes in the context of the OpenClaw assistant environment without any integrity verification.

Affected Products

OpenClaw versions prior to 2026.4.8
OpenClaw Node.js implementations (cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*)

Discovery Timeline

2026-04-28 - CVE-2026-42428 published to NVD
2026-04-30 - Last updated in NVD database

Technical Details for CVE-2026-42428

Vulnerability Analysis

This vulnerability stems from a Missing Integrity Check (CWE-353) in OpenClaw's plugin download mechanism. When users download plugin archives, the application fails to verify the integrity of the downloaded packages before installation. This creates a window of opportunity for attackers to perform man-in-the-middle attacks or supply chain compromises where malicious or tampered plugin packages can be substituted without any detection mechanism alerting the user or the system.

The vulnerability requires network access and some user interaction, along with low-privilege authentication to the system. When successfully exploited, an attacker can achieve high impact on confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause lies in the src/infra/net/fetch-guard.ts module where DNS pinning logic was improperly ordered. The original implementation performed DNS resolution before determining whether a trusted environment proxy should be used, creating a race condition where unpinned requests could bypass integrity controls. The security patch restructures the code flow to only perform DNS pinning resolution when necessary, after trusted proxy checks have been completed.

Attack Vector

The attack vector is network-based, requiring an attacker to position themselves to intercept plugin download traffic. The exploitation requires:

Network Position: Attacker must be able to intercept network traffic between the OpenClaw client and plugin repositories
User Interaction: A user must initiate a plugin download action
Low Privileges: The attacker needs minimal authentication to leverage the vulnerability

Without integrity verification, substituted malicious packages are accepted and installed as legitimate plugins, potentially executing arbitrary code within the OpenClaw environment.

typescript

     try {
       assertExplicitProxySupportsPinnedDns(parsedUrl, params.dispatcherPolicy, params.pinDns);
       await assertExplicitProxyAllowed(params.dispatcherPolicy, params.lookupFn, params.policy);
-      const pinned = await resolvePinnedHostnameWithPolicy(parsedUrl.hostname, {
-        lookupFn: params.lookupFn,
-        policy: params.policy,
-      });
       const canUseTrustedEnvProxy =
         mode === GUARDED_FETCH_MODE.TRUSTED_ENV_PROXY && hasProxyEnvConfigured();
       if (canUseTrustedEnvProxy) {
         dispatcher = createHttp1EnvHttpProxyAgent();
       } else if (params.pinDns === false) {
         dispatcher = createPolicyDispatcherWithoutPinnedDns(params.dispatcherPolicy);
       } else {
+        const pinned = await resolvePinnedHostnameWithPolicy(parsedUrl.hostname, {
+          lookupFn: params.lookupFn,
+          policy: params.policy,
+        });
         dispatcher = createPinnedDispatcher(pinned, params.dispatcherPolicy, params.policy);
       }

Source: GitHub Commit Update

Detection Methods for CVE-2026-42428

Indicators of Compromise

Unexpected plugin installations or plugin files that do not match known checksums
Network traffic anomalies during plugin download operations, particularly DNS resolution failures followed by successful downloads
Modified or unsigned plugin archives in the OpenClaw plugins directory
Unusual process execution originating from the OpenClaw assistant environment

Detection Strategies

Monitor network traffic for plugin download requests that bypass expected proxy configurations
Implement file integrity monitoring on the OpenClaw plugins directory to detect unauthorized modifications
Compare installed plugin checksums against vendor-published integrity hashes
Deploy network intrusion detection rules to identify potential man-in-the-middle attacks targeting OpenClaw traffic

Monitoring Recommendations

Enable verbose logging in OpenClaw to capture plugin installation events and network resolution behavior
Set up alerts for any plugin installations that occur outside of scheduled maintenance windows
Monitor for DNS resolution anomalies that may indicate DNS spoofing attempts
Implement egress traffic analysis to detect connections to unexpected plugin repositories

How to Mitigate CVE-2026-42428

Immediate Actions Required

Upgrade OpenClaw to version 2026.4.8 or later immediately
Audit all currently installed plugins for integrity and remove any suspicious packages
Review network logs for evidence of past exploitation attempts
Temporarily disable plugin auto-update functionality until the patch is applied

Patch Information

The security patch is available in OpenClaw version 2026.4.8 and later. The fix restructures the DNS pinning logic in src/infra/net/fetch-guard.ts to ensure integrity verification occurs at the correct point in the request flow. The patch commit d7c3210cd6f5fdfdc1beff4c9541673e814354d5 addresses this vulnerability by moving DNS resolution inside the conditional block where it is actually needed.

For detailed information, refer to the GitHub Security Advisory and the VulnCheck Advisory.

Workarounds

Configure OpenClaw to only download plugins from trusted, verified sources over HTTPS
Deploy a local proxy with SSL inspection to validate plugin download integrity
Restrict network access for the OpenClaw process to only allow connections to known, legitimate plugin repositories
Implement application-level firewall rules to block connections to untrusted endpoints

bash

# Configuration example - Restrict OpenClaw to trusted plugin sources only
# Add to OpenClaw configuration file
export OPENCLAW_PLUGIN_SOURCES="https://plugins.openclaw.io"
export OPENCLAW_VERIFY_SSL=true
export OPENCLAW_PROXY_MODE="trusted_env"