CVE-2026-31992: Openclaw Auth Bypass Vulnerability

CVE-2026-31992 Overview

OpenClaw versions prior to 2026.2.23 contain an allowlist bypass vulnerability in the system.run guardrails component that enables authenticated operators to execute unintended commands. The vulnerability exists in the execution wrapper mechanism, where an attacker can leverage /usr/bin/env with the -S flag to bypass policy analysis and execute arbitrary shell wrapper payloads at runtime.

This authorization bypass represents a significant security gap in OpenClaw's command execution security model, allowing trusted operators to circumvent intended restrictions on executable commands.

Critical Impact

Authenticated attackers can bypass allowlist controls to execute arbitrary commands, potentially leading to unauthorized system access, data manipulation, or privilege escalation within Node.js environments running OpenClaw.

Affected Products

• OpenClaw versions prior to 2026.2.23
• OpenClaw Node.js package (cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*)

Discovery Timeline

• 2026-03-19 - CVE CVE-2026-31992 published to NVD
• 2026-03-19 - Last updated in NVD database

Technical Details for CVE-2026-31992

Vulnerability Analysis

The vulnerability stems from an incomplete implementation of allowlist enforcement in OpenClaw's execution wrapper guardrails. When /usr/bin/env is included in the allowlist of permitted executables, the env -S (split string) option can be exploited to chain arbitrary commands that would otherwise be blocked by policy analysis.

The env -S flag allows splitting of command arguments, effectively enabling attackers to construct shell wrapper payloads that bypass the static analysis performed by the guardrail system. This creates a discrepancy between what the policy analyzer sees and what actually gets executed at runtime.

The root issue lies in the execution path where policy evaluation occurs before the effective argument vector is resolved, allowing crafted inputs to appear benign during policy checks but execute malicious payloads during actual command execution.

Root Cause

The vulnerability originates from CWE-184 (Incomplete List of Disallowed Inputs). The allowlist mechanism failed to account for the behavioral characteristics of /usr/bin/env when used with the -S flag, which enables string splitting and command chaining. The policy analysis examined the initial command arguments without considering how env -S transforms and executes subsequent payload strings.

The security fix introduces buildEnforcedShellCommand to replace the previous buildSafeBinsShellCommand and buildSafeShellCommand functions, ensuring execution parity between policy analysis and actual runtime execution.

Attack Vector

The attack vector is network-based, requiring authentication as an operator within the OpenClaw system. An attacker with valid operator credentials can craft specially formatted commands that exploit the env -S bypass:

1. The attacker identifies that /usr/bin/env is allowlisted
2. They construct a payload using env -S to split and inject additional commands
3. The policy analyzer evaluates the command as a benign env invocation
4. At runtime, the -S flag causes the string to be split and executed as separate commands
5. Arbitrary payloads execute outside the intended allowlist restrictions

The following patch demonstrates the security fix implemented to address this vulnerability:

   addAllowlistEntry,
   type ExecAsk,
   type ExecSecurity,
-  buildSafeBinsShellCommand,
-  buildSafeShellCommand,
+  buildEnforcedShellCommand,
   evaluateShellAllowlist,
   maxAsk,
   minSecurity,

Source: GitHub Commit

The fix also adds policy blocking checks and effective argument vector evaluation:

   const segmentSatisfiedBy: ExecSegmentSatisfiedBy[] = [];
 
   const satisfied = segments.every((segment) => {
+    if (segment.resolution?.policyBlocked === true) {
+      segmentSatisfiedBy.push(null);
+      return false;
+    }
+    const effectiveArgv =
+      segment.resolution?.effectiveArgv && segment.resolution.effectiveArgv.length > 0
+        ? segment.resolution.effectiveArgv
+        : segment.argv;
     const candidatePath = resolveAllowlistCandidatePath(segment.resolution, params.cwd);
     const candidateResolution =
       candidatePath && segment.resolution

Source: GitHub Commit

Detection Methods for CVE-2026-31992

Indicators of Compromise

• Unusual command executions involving /usr/bin/env -S with concatenated or encoded payloads
• Process execution logs showing env invocations followed by unexpected child processes
• Audit logs indicating operator commands that diverge from typical operational patterns
• Shell wrapper scripts or payloads being executed outside normal workflow contexts

Detection Strategies

• Monitor process execution chains for env -S usage patterns, particularly when followed by shell interpreters or script execution
• Implement behavioral analysis to detect command executions that bypass normal allowlist validation
• Review OpenClaw operator activity logs for anomalous command patterns or policy bypass attempts
• Deploy endpoint detection to identify command injection patterns characteristic of this bypass technique

Monitoring Recommendations

• Enable verbose logging for OpenClaw's system.run guardrail component to capture all command execution attempts
• Configure alerts for any use of env -S syntax within operator command contexts
• Implement real-time monitoring of process ancestry to detect unexpected command chaining
• Review and audit allowlist configurations regularly to identify potentially dangerous entries like /usr/bin/env

How to Mitigate CVE-2026-31992

Immediate Actions Required

• Upgrade OpenClaw to version 2026.2.23 or later immediately
• Review current allowlist configurations and remove /usr/bin/env if not strictly required
• Audit operator command logs for any evidence of exploitation attempts
• Implement additional monitoring for env -S command patterns until patching is complete

Patch Information

The vulnerability has been addressed in OpenClaw version 2026.2.23. Security patches are available through the following commits:

• Security Patch Commit 3f923e8
• Security Patch Commit a1c4bf0

For detailed information, refer to the GitHub Security Advisory GHSA-48wf-g7cp-gr3m.

Workarounds

• Remove /usr/bin/env from the execution allowlist until the patch can be applied
• Implement network-level controls to restrict operator access to trusted IP ranges
• Deploy additional command execution monitoring to detect bypass attempts
• Consider implementing a deny-list for env -S patterns as an interim measure

# Configuration example - Remove env from allowlist
# Review your OpenClaw configuration and remove potentially dangerous entries
# Example: Edit your allowlist configuration to exclude /usr/bin/env

# Before (vulnerable):
# allowlist: ["/usr/bin/env", "/bin/ls", "/usr/bin/cat"]

# After (mitigated):
# allowlist: ["/bin/ls", "/usr/bin/cat"]