Improper Authentication in LiteLLM - CVE-2026-35030
Published: April 7, 2026
Vulnerability identifier: #VU125066
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-35030
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: LiteLLM
Affected software:
LiteLLM
LiteLLM
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authentication and assume a legitimate user's identity and permissions.
The vulnerability exists due to improper authentication in the OIDC userinfo cache when processing JWT authentication tokens with colliding cache keys. A remote attacker can craft a token whose first 20 characters match a legitimate user's cached token to bypass authentication and assume a legitimate user's identity and permissions.
Only deployments with JWT/OIDC authentication enabled are vulnerable, and the issue depends on a cached legitimate user's token being present.
How to mitigate CVE-2026-35030
Install security update from vendor's website.