CVE-2025-59466 & CVE-2026-21636: What Moltbot Users Need to Know

Two significant CVEs have been disclosed affecting Moltbot deployments. This guide explains the vulnerabilities, who’s affected, and how to remediate.

Quick Summary

CVE	Severity	Affected Versions	Patched In
CVE-2025-59466	High	< 1.2.3	1.2.3+
CVE-2026-21636	Medium	< 1.3.0	1.3.0+

If you’re running an affected version, update immediately.

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CVE-2025-59466: Gateway Authentication Bypass

Overview

A vulnerability in the gateway authentication mechanism allowed attackers to bypass token validation under specific conditions.

Technical Details

• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• CVSS Score: 8.6 (High)

How It Works

The vulnerability exploited a race condition in token validation:

1. Attacker sends request with malformed token
2. Validation thread begins checking token
3. Second request arrives before validation completes
4. Race condition allows second request to bypass auth

Who’s Affected

• Deployments running Moltbot gateway < 1.2.3
• Gateways exposed to untrusted networks
• Configurations without rate limiting

Am I Vulnerable?

Check your version:

moltbot --version

If the output shows a version less than 1.2.3, you’re affected.

Remediation

Option 1: Update (Recommended)

npm update -g moltbot
# or
pip install --upgrade moltbot

Option 2: Mitigations (if update not immediately possible)

1. Restrict gateway to localhost only:

   { "gateway": { "bind": "127.0.0.1" } }

2. Enable aggressive rate limiting:

   { "rateLimiting": { "requestsPerMinute": 10 } }

3. Use a reverse proxy with additional auth

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CVE-2026-21636: Tool Permission Escalation

Overview

A flaw in the tool permission system allowed agents to escalate privileges beyond configured restrictions.

Technical Details

• Attack Vector: Local
• Attack Complexity: High
• Privileges Required: Low
• User Interaction: Required
• CVSS Score: 5.3 (Medium)

How It Works

The vulnerability chain:

1. Attacker crafts prompt that appears benign
2. Prompt triggers tool A (which is allowed)
3. Tool A's output contains instruction to invoke Tool B
4. Permission check fails to catch the indirect invocation
5. Tool B executes with elevated permissions

Who’s Affected

• Deployments with mixed tool permission levels
• Agents processing untrusted content
• Configurations without output validation

Am I Vulnerable?

You’re at risk if:

• Running version < 1.3.0
• Have both restricted and unrestricted tools enabled
• Process external content (PRs, issues, etc.)

Remediation

Option 1: Update (Recommended)

npm update -g moltbot

Option 2: Mitigations

1. Disable elevated tools when processing untrusted content
2. Use separate agent profiles for different trust levels:

   {
     "profiles": {
       "trusted": { "tools": ["all"] },
       "untrusted": { "tools": ["read-only"] }
     }
   }

3. Implement output validation

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Verification Steps

After patching, verify your deployment:

1. Confirm Version

moltbot --version
# Should show >= 1.3.0

2. Run Security Audit

moltbot security audit --include-cve-checks

3. Check Configuration

# Verify auth is enabled
moltbot config show --section=auth

# Verify tool restrictions
moltbot tools list --show-permissions

4. Review Logs

Check for any suspicious activity during the vulnerable period:

moltbot logs --since "2025-12-01" --filter "auth_failure|permission_escalation"

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Timeline

Date	Event
2025-11-15	CVE-2025-59466 discovered by security researcher
2025-11-20	Reported to Anthropic security team
2025-12-01	Patch developed and tested
2025-12-15	Version 1.2.3 released with fix
2026-01-05	CVE-2026-21636 discovered internally
2026-01-15	Version 1.3.0 released with fix
2026-01-20	Public disclosure

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Lessons Learned

These CVEs highlight important security principles for AI agents:

1. Defense in Depth

Don’t rely on a single security control. Layer your defenses:

• Authentication + Authorization + Network restrictions + Monitoring

2. Least Privilege

Limit tool access to what’s actually needed. The escalation vulnerability was worse for deployments with broad permissions.

3. Update Promptly

Both vulnerabilities were patched before public disclosure. Organizations with good update practices were protected.

4. Trust No Input

Assume all input—including content the agent reads—could be malicious.

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Need Help?

• Security Audit Checklist - Comprehensive audit guide
• Gateway Hardening - Secure your configuration
• Anthropic Security: [email protected] for urgent CVE-related issues

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Stay updated on security vulnerabilities by bookmarking SecureMolt.com. We’ll publish guidance for future disclosures.