CVE-2025-69220: LibreChat Auth Bypass Vulnerability

CVE-2025-69220 Overview

CVE-2025-69220 is a Broken Access Control vulnerability affecting LibreChat, an open-source ChatGPT clone with additional features. Version 0.8.1-rc2 fails to enforce proper access control for file uploads to an agent's file context and file search functionality. An authenticated attacker with knowledge of an agent ID can manipulate the behavior of arbitrary agents by uploading new files to the file context or file search, even without possessing the required permissions for that agent.

This vulnerability aligns with OWASP Top 10: Broken Access Control, which is the most critical web application security risk. The flaw enables unauthorized modification of agent behavior through malicious file uploads, potentially affecting the integrity of AI agent responses and causing service disruption.

Critical Impact

Authenticated attackers can bypass authorization controls to modify arbitrary agent behavior by uploading malicious files, compromising agent integrity and potentially affecting downstream users relying on those agents.

Affected Products

• LibreChat version 0.8.1-rc2
• LibreChat versions prior to 0.8.2-rc2

Discovery Timeline

• 2026-01-07 - CVE-2025-69220 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-69220

Vulnerability Analysis

This vulnerability stems from missing authorization checks in the file upload endpoints for LibreChat agents. The application accepts file uploads to agent file contexts without properly verifying that the authenticated user has the necessary permissions to modify the target agent. This represents a classic authorization bypass scenario where authentication is present but authorization enforcement is absent.

The vulnerability is classified under CWE-284 (Improper Access Control), which describes flaws where software does not properly restrict access to resources. Additionally, this maps to CWE-862 (Missing Authorization), indicating the absence of authorization checks entirely for the affected functionality.

The attack requires network access and low-privileged authentication, meaning an attacker needs a valid account on the LibreChat instance but can then manipulate agents belonging to other users or the system.

Root Cause

The root cause is the absence of permission validation in the file upload handler for agent file contexts. The application's api/server/routes/files/files.js module did not verify whether the requesting user had appropriate permissions (such as agent ownership or administrative rights) before allowing file uploads to be associated with an agent's context.

The security patch introduces proper permission checks by importing SystemRoles and implementing authorization validation to ensure users can only upload files to agents they are permitted to modify.

Attack Vector

The attack exploits the network-accessible file upload API. An authenticated attacker can:

1. Obtain or enumerate valid agent IDs (which may be exposed through the application interface)
2. Craft file upload requests targeting agents they do not own or have permission to modify
3. Upload malicious or misleading files to the agent's file context or file search
4. Alter the agent's behavior when it references these uploaded files during operation

This can lead to integrity compromise of agent responses, potential information manipulation, and service disruption for legitimate agent users.

// Security patch from api/server/routes/files/files.js
// Source: https://github.com/danny-avila/LibreChat/commit/4b9c6ab1cb9de626736de700c7981f38be08d237

   isUUID,
   CacheKeys,
   FileSources,
+  SystemRoles,
   ResourceType,
   EModelEndpoint,
   PermissionBits,

Source: GitHub Commit for LibreChat

The patch adds the SystemRoles import, enabling proper role-based permission checks before processing file uploads to agent contexts.

Detection Methods for CVE-2025-69220

Indicators of Compromise

• Unexpected file uploads appearing in agent file contexts from users who should not have access
• Log entries showing file upload requests to agent endpoints from non-owner user sessions
• Agents exhibiting modified or unexpected behavior due to unauthorized file context changes
• Increased file upload activity targeting multiple agent IDs from a single user account

Detection Strategies

• Implement logging for all file upload operations to agent contexts, including user ID, agent ID, and permission status
• Monitor for patterns of users attempting to upload files to agents they do not own
• Review application logs for failed authorization attempts that may indicate probing activity
• Enable audit trails for agent configuration and file context modifications

Monitoring Recommendations

• Configure alerts for file upload requests where the user does not match the agent owner
• Monitor API endpoint access patterns for the files upload routes
• Implement rate limiting on file upload endpoints to slow enumeration attacks
• Review agent file contexts periodically for unexpected or unauthorized content

How to Mitigate CVE-2025-69220

Immediate Actions Required

• Upgrade LibreChat to version 0.8.2-rc2 or later immediately
• Audit existing agent file contexts for any unauthorized or suspicious uploads
• Review access logs for potential exploitation attempts prior to patching
• Verify that all deployed LibreChat instances are running the patched version

Patch Information

The vulnerability is fixed in LibreChat version 0.8.2-rc2. The security patch implements proper permission checks using SystemRoles and PermissionBits to validate user authorization before allowing file uploads to agent contexts.

• Fixed Version:0.8.2-rc2
• Security Commit:4b9c6ab1cb9de626736de700c7981f38be08d237
• Release Notes:LibreChat Release v0.8.2-rc2
• Security Advisory:GHSA-xcmf-rpmh-hg59

Workarounds

• Restrict network access to the LibreChat instance to trusted users only until patching is complete
• Implement web application firewall (WAF) rules to monitor and potentially block suspicious file upload patterns
• Disable agent file upload functionality temporarily if the feature is not critical to operations
• Review and limit user account creation to reduce the pool of potential authenticated attackers

# Configuration example - Update LibreChat to patched version
# Pull the latest patched release
git fetch --all --tags
git checkout v0.8.2-rc2

# Rebuild and restart the application
npm install
npm run build
npm run start