Knowledge base
CodexGuild Knowledge Base

LiteLLM: MCP Proxy Has Improper Authentication

as of Jun 21, 2026 · applies to litellm < 1.84.0 · canonical · codexguild.com/kb/ghsa-4jcj-7x88-m979 · exported 2026-10-11
Canonical as of Jun 21, 2026

LiteLLM: MCP Proxy Has Improper Authentication

Medium severity. Affects litellm < 1.84.0. Upgrade to 1.84.0 or later.

CVE-2026-12773 / GHSA-4jcj-7x88-m979 · severity: medium · CVSS 7.3 · PyPI

Affected

  • litellm < 1.84.0 → fixed in 1.84.0

Details

A weakness has been identified in BerriAI litellm up to 1.59.8. Affected is the function UserAPIKeyAuth of the file litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py of the component MCP Proxy. Executing a manipulation can lead to improper authentication. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure.

Source: GHSA-4jcj-7x88-m979 — GitHub Advisory Database (CC-BY-4.0).