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.

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Source ID Title
Github GHSA Github GHSA GHSA-jjhc-v7c2-5hh6 LiteLLM: Authentication bypass via OIDC userinfo cache key collision
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 07 Apr 2026 20:45:00 +0000

Type Values Removed Values Added
First Time appeared Litellm
Litellm litellm
CPEs cpe:2.3:a:litellm:litellm:*:*:*:*:*:*:*:*
Vendors & Products Litellm
Litellm litellm

Tue, 07 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 07 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
First Time appeared Berriai
Berriai litellm
Vendors & Products Berriai
Berriai litellm

Mon, 06 Apr 2026 18:00:00 +0000

Type Values Removed Values Added
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.
Title LiteLLM has an authentication bypass via OIDC userinfo cache key collision
Weaknesses CWE-287
References
Metrics cvssV4_0

{'score': 9.4, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-07T14:24:34.782Z

Reserved: 2026-03-31T21:06:06.427Z

Link: CVE-2026-35030

cve-icon Vulnrichment

Updated: 2026-04-07T14:24:28.779Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-06T17:17:12.650

Modified: 2026-04-07T20:20:56.653

Link: CVE-2026-35030

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-06T21:31:33Z

Weaknesses