CVE-2026-35650: Openclaw RCE Vulnerability

CVE-2026-35650 Overview

CVE-2026-35650 is an environment variable override handling vulnerability in OpenClaw before version 2026.3.22. The vulnerability exists due to inconsistent sanitization paths that allow attackers to bypass the shared host environment policy. By supplying blocked or malformed override keys that slip through inconsistent validation, attackers can execute arbitrary code with unintended environment variables.

This vulnerability is classified as CWE-15 (External Control of System or Configuration Setting), highlighting the risk of allowing external input to influence critical system settings. OpenClaw, a Node.js package, is susceptible when processing environment variable overrides, making shared hosting environments particularly vulnerable.

Critical Impact

Successful exploitation allows attackers to bypass security policies and execute arbitrary code with manipulated environment variables, potentially compromising the integrity and confidentiality of affected systems.

Affected Products

• OpenClaw versions prior to 2026.3.22
• OpenClaw for Node.js (all platforms)
• Shared hosting environments utilizing OpenClaw

Discovery Timeline

• 2026-04-10 - CVE-2026-35650 published to NVD
• 2026-04-13 - Last updated in NVD database

Technical Details for CVE-2026-35650

Vulnerability Analysis

The vulnerability stems from inconsistent input validation when processing environment variable override requests. OpenClaw implements a shared host environment policy designed to prevent unauthorized modification of critical environment variables. However, the sanitization logic contains inconsistencies that create exploitable gaps.

When an attacker submits specially crafted override keys—either blocked names in unexpected formats or malformed key structures—the validation pathway fails to properly reject these inputs. This inconsistency between different validation stages allows malicious environment variable overrides to bypass security controls and reach the execution context.

The network-accessible nature of this vulnerability, combined with the ability to execute code with modified environment variables, creates significant risk for multi-tenant and shared hosting deployments where environment isolation is critical for security.

Root Cause

The root cause is inconsistent input sanitization across multiple validation pathways in the environment variable override handling code. Different code paths apply different sanitization rules, creating gaps where certain input patterns pass initial checks but carry malicious payloads that affect downstream processing. This inconsistency allows attackers to craft inputs that appear benign to early validation stages while still achieving their malicious objective of overriding protected environment variables.

Attack Vector

The attack is network-based and requires low privileges to execute. An authenticated attacker can exploit this vulnerability by:

1. Identifying the environment variable override mechanism in OpenClaw
2. Crafting override keys that exploit inconsistencies between validation stages
3. Submitting the malformed or specially formatted keys through the override interface
4. Bypassing the shared host environment policy protections
5. Executing code with manipulated environment variables that were supposed to be protected

The vulnerability mechanism involves inconsistent sanitization between validation stages, where blocked environment variable keys can be encoded or formatted in ways that bypass initial checks but are still processed downstream. For detailed technical analysis, refer to the GitHub Security Advisory and the VulnCheck Advisory.

Detection Methods for CVE-2026-35650

Indicators of Compromise

• Unusual or malformed environment variable names in application logs
• Unexpected environment variable values in process dumps or debugging output
• Application behavior inconsistent with configured environment settings
• Log entries showing repeated attempts to set protected environment variables

Detection Strategies

• Monitor for anomalous patterns in environment variable override requests, particularly those with unusual encoding or formatting
• Implement application-level logging to capture all environment variable modification attempts
• Deploy runtime application self-protection (RASP) solutions to detect environment manipulation attempts
• Review audit logs for patterns suggesting environment policy bypass attempts

Monitoring Recommendations

• Enable verbose logging for environment variable handling in OpenClaw applications
• Set up alerts for failed validation attempts followed by successful overrides
• Monitor process environment states for unexpected modifications
• Implement integrity checking for critical environment variables at application startup

How to Mitigate CVE-2026-35650

Immediate Actions Required

• Upgrade OpenClaw to version 2026.3.22 or later immediately
• Review application logs for signs of exploitation attempts
• Audit current environment variable configurations for unauthorized modifications
• Implement additional input validation at the application boundary layer

Patch Information

The vulnerability has been addressed in OpenClaw version 2026.3.22. Security patches are available through the official OpenClaw repository:

• Security Patch Commit 630f1479
• Security Patch Commit 7abfff75
• GitHub Security Advisory GHSA-39pp-xp36-q6mg

Workarounds

• Implement strict allowlist-based validation for all environment variable override requests at the application or proxy layer
• Disable or restrict the environment variable override feature if not required for operations
• Deploy network segmentation to limit access to affected OpenClaw instances
• Use containerization with read-only environment configurations where possible

# Update OpenClaw to patched version
npm update openclaw@2026.3.22

# Verify installed version
npm list openclaw