Vulnerability Description
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Authorization header to trigger an OAuth2 passthrough fallback path that replaced failed LiteLLM key validation with an empty UserAPIKeyAuth() object, allowing requests to reach MCP tooling without a valid LiteLLM key. This issue is fixed in version 1.84.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Litellm | Litellm | < 1.84.0 |
Related Weaknesses (CWE)
References
- https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6cPatch
- https://github.com/BerriAI/litellm/pull/26463Issue TrackingPatch
- https://github.com/BerriAI/litellm/releases/tag/v1.84.0ProductRelease Notes
- https://github.com/BerriAI/litellm/security/advisories/GHSA-7488-6r32-c95qMitigationPatchVendor Advisory
FAQ
What is CVE-2026-59822?
CVE-2026-59822 is a vulnerability with a CVSS score of 8.2 (HIGH). LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Au...
How severe is CVE-2026-59822?
CVE-2026-59822 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59822?
Check the references section above for vendor advisories and patch information. Affected products include: Litellm Litellm.