LiteLLM contains a weak authentication vulnerability that allows an attacker holding a valid JWT from the configured identity provider to authenticate as any existing user by exploiting an email-based fallback lookup in the JWT authentication flow without verifying the email_verified claim. Attackers can present a token with an unverified email address matching a victim's account to inherit the victim's role, including proxy_admin privileges, and permanently overwrite the victim's stored identity binding to retain persistent unauthorized access to administrative endpoints exposing API keys and user management.
https://www.vulncheck.com/advisories/litellm-weak-jwt-authentication-via-email-based-user-lookup
https://www.ox.security/blog/litellm-an-ordinary-login-token-can-become-someone-elses-admin-account/
Published: 2026-09-28
Updated: 2026-09-30
Base Score: 8.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:N
Severity: High
Base Score: 8.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Severity: High
Base Score: 7.6
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00273