SB2026040720 - Multiple vulnerabilities in LibreChat

Description

This security bulletin contains information about 2 vulnerabilities.

1) Path traversal (CVE-ID: CVE-2026-34371)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/U:Green

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in execute_code. A remote user can send a specially crafted HTTP request and write arbitrary files on the system.

2) Improper access control (CVE-ID: CVE-2026-44653)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to improper access control in the MCP server configuration API endpoints when handling requests for shared MCP server configurations. A remote user can send a request to the MCP server listing or single-server endpoint to disclose sensitive information.

Exposed plaintext values include admin-managed API keys and OAuth client secrets for shared MCP servers.

Remediation

Install update from vendor's website.

References

• https://github.com/danny-avila/LibreChat/security/advisories/GHSA-qrm5-r67f-6692
• https://github.com/danny-avila/LibreChat/security/advisories/GHSA-6vqg-rgpm-qvf9