VULNERABILITY INTELLIGENCE

CVE-2026-59822

CVSS score8.2 HIGH

EPSS probability0.84%

CISA KEVKnown exploited vulnerability

Published2026-07-08

Last modified2026-10-25

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Known Exploited Vulnerability

BerriAI LiteLLM Improper Authentication Vulnerability

Vendor / product: BerriAI / LiteLLM

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.

Weakness classification

security-advisories@github.com: CWE-287

Primary references

security-advisories@github.com — Patch
security-advisories@github.com — Issue Tracking, Patch
security-advisories@github.com — Product, Release Notes
security-advisories@github.com — Mitigation, Patch, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0 — US Government Resource
134c704f-9b21-4f2e-91b3-4a467353bcc0 — Third Party Advisory