CVE-2026-54030

LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow

Published Jun 25, 2026 CVSS 3.1 · 8 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Danny-avila
Danny-avila libre Chat
Vendors & Products Danny-avila
Danny-avila libre Chat
Type Values Removed Values Added
Description 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.
Title LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow
Weaknesses CWE-346
References
Metrics cvssV3_1

{'score': 8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 26, 2026, 2:04 AM
Reserved
Jun 11, 2026, 4:57 PM
Status
Analyzed
Published
Jun 25, 2026, 5:16 PM
Modified
Oct 25, 2026, 10:10 PM