CVE-2026-27524: Openclaw Auth Bypass Vulnerability

CVE-2026-27524 Overview

CVE-2026-27524 is a prototype pollution vulnerability affecting OpenClaw versions prior to 2026.2.21. The vulnerability exists in the runtime /debug set override functionality, which improperly accepts prototype-reserved keys in object values. Authorized callers of the /debug set endpoint can inject __proto__, constructor, or prototype keys to manipulate object prototypes and potentially bypass command gate restrictions.

Prototype pollution attacks allow adversaries to inject properties into JavaScript object prototypes, which can lead to property injection across all objects inheriting from the polluted prototype. In this case, the attack surface is limited to authorized debug callers, reducing the overall exploitability.

Critical Impact

Authorized users with access to the /debug set endpoint can manipulate object prototypes, potentially bypassing command gate restrictions and altering application behavior.

Affected Products

• OpenClaw versions prior to 2026.2.21 (Node.js package)

Discovery Timeline

• 2026-03-18 - CVE-2026-27524 published to NVD
• 2026-03-18 - Last updated in NVD database

Technical Details for CVE-2026-27524

Vulnerability Analysis

This prototype pollution vulnerability (CWE-1321) allows authorized callers of the /debug set endpoint to inject prototype-reserved keys such as __proto__, constructor, or prototype into runtime command override object values. When these keys are accepted without validation, attackers can pollute the Object prototype, causing injected properties to propagate to all objects that inherit from it.

The impact of this vulnerability is primarily on integrity. Exploitation requires prior authorization to access the debug interface, which limits the attack surface. However, successful exploitation could allow an attacker to bypass command gate restrictions, potentially escalating their capabilities within the OpenClaw application.

Root Cause

The root cause is insufficient input validation in the runtime command override mechanism. The application failed to sanitize or reject prototype-reserved keys (__proto__, constructor, prototype) when processing user-supplied object values through the debug interface. This allowed these special keys to be written directly to object prototypes rather than being treated as regular object properties.

Attack Vector

The attack requires network access and authentication to the /debug set endpoint. An attacker with legitimate access to the debug interface can craft malicious requests containing prototype-reserved keys. When processed, these keys modify the object prototype chain rather than creating standard object properties, affecting all objects that share the polluted prototype.

// Security patch in src/auto-reply/commands-registry.ts
// fix(security): harden runtime command override gating

 import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "../agents/defaults.js";
 import { resolveConfiguredModelRef } from "../agents/model-selection.js";
 import type { SkillCommandSpec } from "../agents/skills.js";
+import { isCommandFlagEnabled } from "../config/commands.js";
 import type { OpenClawConfig } from "../config/types.js";
 import { escapeRegExp } from "../utils.js";
 import { getChatCommands, getNativeCommandSurfaces } from "./commands-registry.data.js";

Source: GitHub Commit Update

The patch introduces the isCommandFlagEnabled function to properly validate and gate runtime command overrides, preventing prototype pollution through the debug interface.

// Security patch in src/auto-reply/reply/bash-command.ts
// fix(security): harden runtime command override gating

 import { createExecTool } from "../../agents/bash-tools.js";
 import { resolveSandboxRuntimeStatus } from "../../agents/sandbox.js";
 import { killProcessTree } from "../../agents/shell-utils.js";
+import { isCommandFlagEnabled } from "../../config/commands.js";
 import type { OpenClawConfig } from "../../config/config.js";
 import { logVerbose } from "../../globals.js";
 import { clampInt } from "../../utils.js";

Source: GitHub Commit Update

Detection Methods for CVE-2026-27524

Indicators of Compromise

• Unusual requests to /debug set endpoints containing __proto__, constructor, or prototype keys in payload objects
• Application behavior anomalies indicating polluted object prototypes
• Command gate bypasses or unexpected privilege escalation patterns in application logs

Detection Strategies

• Monitor debug endpoint access logs for requests containing prototype-reserved key names in JSON payloads
• Implement runtime property monitoring to detect unexpected properties appearing on object prototypes
• Review audit logs for debug interface usage patterns that deviate from normal authorized access

Monitoring Recommendations

• Enable verbose logging on the OpenClaw debug interface to capture all /debug set operations
• Deploy application-level monitoring to detect prototype pollution attempts through anomalous object property injection
• Alert on any command gate restriction bypass events that may indicate successful exploitation

How to Mitigate CVE-2026-27524

Immediate Actions Required

• Upgrade OpenClaw to version 2026.2.21 or later immediately
• Audit debug interface access logs for any suspicious activity involving prototype-reserved keys
• Review and restrict access to the /debug set endpoint to minimize the attack surface

Patch Information

The vendor has released a security patch in commit fbb79d4013000552d6a2c23b9613d8b3cb92f6b6. The fix hardens runtime command override gating by introducing proper validation through the isCommandFlagEnabled function. Users should upgrade to OpenClaw version 2026.2.21 or later to remediate this vulnerability.

For additional details, refer to the GitHub Security Advisory GHSA-62f6-mrcj-v8h5.

Workarounds

• Restrict access to the /debug set endpoint to only essential personnel using network-level controls or application-level authentication restrictions
• Implement a Web Application Firewall (WAF) rule to block requests containing __proto__, constructor, or prototype keys in JSON payloads
• Disable the debug interface entirely in production environments if not required for operational purposes

# Configuration example - Restrict debug endpoint access
# Add to your reverse proxy configuration (nginx example)
location /debug {
    # Restrict access to trusted IPs only
    allow 10.0.0.0/8;
    deny all;
    
    # Add additional authentication layer
    auth_basic "Debug Access";
    auth_basic_user_file /etc/nginx/.htpasswd;
}