High priorityDisclosed

Advisory · CVE-2026-93355

LiteLLM lets a valid login token become someone else's admin account

LiteLLM's JWT flow falls back to an email-based user lookup without checking the email_verified claim, so a token from the configured identity provider with a victim's email inherits the victim's role, including proxy_admin.

Vendor
BerriAI
Product
LiteLLM
Identifier / CWE
CVE-2026-93355
CWE-1390
Action timing
Immediate
ELI5

Explain it like I’m five

LiteLLM trusts the email address written on a login token without checking whether the identity provider actually verified it. Anyone holding a valid token can write someone else's email on it and be treated as that person.

SIMPLIFIED_ATTACK_PATH04 STEPS
  1. 01Valid token, unverified email

    An attacker obtains a legitimate JWT from the configured identity provider with an unverified email address matching a victim's account.

  2. 02Email fallback lookup

    LiteLLM's JWT authentication flow matches the token to an existing user by email without verifying the email_verified claim.

  3. 03Role inheritance

    The attacker inherits the victim's role, including proxy_admin privileges, gaining access to administrative endpoints that expose API keys and user management.

  4. 04Persistent binding

    The victim's stored identity binding is permanently overwritten, retaining the attacker's unauthorized access even after the original token expires.

What happened

LiteLLM 1.102.1 and earlier contains a weak authentication vulnerability in its JWT flow. An attacker holding a valid JWT from the configured identity provider can authenticate as any existing user by exploiting an email-based fallback lookup that does not verify the email_verified claim. Presenting a token with an unverified email address matching a victim’s account lets the attacker inherit the victim’s role, including proxy_admin privileges, and permanently overwrites the victim’s stored identity binding, retaining persistent unauthorized access to administrative endpoints that expose API keys and user management.

What to do

  1. Inventory LiteLLM proxy deployments, including team-managed and shadow instances.
  2. Upgrade LiteLLM beyond 1.102.1 to a release containing the fix for the email fallback lookup.
  3. Review the user identity bindings in the LiteLLM database for unexpected changes or bindings that do not match the identity provider’s records.
  4. Rotate API keys and rebind user identities; treat any key visible to a proxy_admin as compromised.
  5. Audit administrative endpoint logs for unusual user-management or key-viewing activity.

Management note

This turns any valid low-privilege login token into a potential admin account on the LLM gateway, where API keys are the crown jewels. Patch, verify identity bindings, and rotate keys as one task rather than three.