CVE-2026-54030
Published: 25 June 2026
Summary
CVE-2026-54030 is a high-severity Origin Validation Error (CWE-346) vulnerability in Librechat Librechat. Its CVSS base score is 8.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Application Access Token (T1528); ranked at the 1.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-39457
Vulnerability details
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…
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malicious MCP server to steal access tokens intended for a legitimate server. This vulnerability is fixed in 0.8.5.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
OAuth resource validation failure directly enables theft of application access tokens by a malicious server (T1528).
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires unique identification of the service before communications, addressing failures to validate the origin of the interaction.
Trusted path establishment enforces validation that the communication originates from and reaches only the intended trusted system components.
Enforces validation of the true origin of DNS responses via signatures and chain-of-trust mechanisms.
Enforces origin validation of name/address data, eliminating reliance on unverified or impersonated DNS sources.
Mandates origin validation so that only legitimate endpoints can continue the authenticated session.