CVE-2026-54030: Librechat

Critical severity, CVSS 9.3. EPSS: 0.2% chance of exploitation in the next 30 days.

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.5, LibreChat's MCP OAuth implementation does not validate that the resource parameter from OAuth Protected Resource metadata (RFC 9728) matches the configured MCP server URL, allowing a malicious MCP server to steal access tokens intended for a legitimate server. This vulnerability is fixed in 0.8.5.

Affected products

• Librechat Librechat: up to and including 0.8.4; version 0.8.5 only

Published 2026-06-25. Last modified 2026-06-29.