CVE-2026-49468

Name of the Vulnerable Software and Affected Versions LiteLLM versions prior to 1.84.0

Description A Host-header parsing flaw in the LiteLLM proxy allows unauthenticated access to protected management routes. The authentication layer derives the effective route from request.url.path in the get request route() function within litellm/proxy/auth/auth utils.py, which is reconstructed from the Host header. A crafted Host header can cause the authentication gate to evaluate a different route than the one dispatched by FastAPI, leading to an authentication bypass via Host Header Injection.

Recommendations Update to version 1.84.0 or later. As a temporary workaround, place the proxy behind an upstream component that validates or normalizes the Host header, such as a CDN, WAF, a reverse proxy with explicit server name allowlists, or a cloud load balancer with host-based routing rules, or restrict network access to the proxy listener.