CVE-2026-54030 json
LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow
published 2026-06-25 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-39457
- cvss
- 8.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 6%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N |
| NVD | 3.1 | 9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N |
Affected products
- danny-avila LibreChat
Classification
- Weakness
-
- CWE-346 Origin Validation Error
References
-
github.com
/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23
exploit, vendor-advisory
Sources
- CVE List CVE-2026-54030
- NVD CVE-2026-54030
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