AIIC AI Intelligence Centre

SOURCE-LINKED INTELLIGENCE

GHSA-jjhc-v7c2-5hh6: LiteLLM: Authentication bypass via OIDC userinfo cache key collision

OSV AI package advisories · observation · Apr 3, 2026 · UTC

### Impact 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. ### Patches Fixed in v1.83.

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recordType
vulnerability
status
active
evidenceStatus
reported
region
Global

Evidence & attribution

First collected: 2026-09-20T23:41:51.992Z. This is not the publication date.