VULNERABILITY INTELLIGENCE

CVE-2026-35030

CVSS score9.1 CRITICAL
EPSS probability0.63%
CISA KEVNot currently listed
Published2026-04-06
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Description

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.83.0, when JWT authentication is enabled (enable_jwt_auth: true), the OIDC userinfo cache uses token[:20] as the cache key. JWT headers produced by the same signing algorithm generate identical first 20 characters. This configuration option is not enabled by default. Most instances are not affected. An unauthenticated attacker can craft a token whose first 20 characters match a legitimate user's cached token. On cache hit, the attacker inherits the legitimate user's identity and permissions. This affects deployments with JWT/OIDC authentication enabled. Fixed in v1.83.0.

Weakness classification

  • security-advisories@github.com: CWE-287
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-222

Primary references