Paper/Archive/CVE-2026-54030

CVE-2026-54030

danny-avila LibreChat — LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow

CVSS 9.3 (NVD)9.3 / 10 × 3027.9 Not in CISA KEV+300.0 EPSS percentile 6.0.060 × 201.2 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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

ProductAffectedFixed inSource

LibreChat< 0.8.5–CNA

Scores by source

NVD9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

GitHub_M (CNA)8.0CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23