CVE-2026-35030
criticalpriority · track · 10EPSS 0.006 · 50 %ileexploit · PoCEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.9–9.4
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (1)
Public proof-of-concept and weaponised exploit code.
affected products (3)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-jjhc-v7c2-5hh6LiteLLM: Authentication bypass via OIDC userinfo cache key collision2026-04-03ghsa · osvUS
### 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 v1.83.0. The cache key now uses the full hash of the JWT token. ### Workarounds Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.
- PYSEC-2026-390LiteLLM: Authentication bypass via OIDC userinfo cache key collision2026-06-29vendor · osvUS
### 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 v1.83.0. The cache key now uses the full hash of the JWT token. ### Workarounds Disable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.
also known as (6)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://github.com/BerriAI/litellm/releasesPatchcnnvd
- https://github.com/BerriAI/litellm/security/advisories/GHSA-jjhc-v7c2-5hh6cnnvd
- https://github.com/BerriAI/litellm/security/advisories/GHSA-jjhc-v7c2-5hh6enisa_euvd
- https://access.redhat.com/errata/RHSA-2026:13545nvd
- https://access.redhat.com/errata/RHSA-2026:28960nvd
- https://access.redhat.com/errata/RHSA-2026:30056nvd
- https://access.redhat.com/security/cve/CVE-2026-35030nvd
- https://bugzilla.redhat.com/show_bug.cgi?id=2455509nvd
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