| Package | Affected versions | Patched versions |
|---|---|---|
| litellm | < 1.84.0 | 1.84.0 |
| litellm | < 1.84.0 | 1.84.0 |
A Host-header parsing flaw in the LiteLLM proxy could, under specific conditions, allow unauthenticated access to protected management routes.
The auth layer derived the effective route from request.url.path in litellm/proxy/auth/auth_utils.py::get_request_route(), which Starlette reconstructs from the Host header. A crafted Host could therefore make the auth gate evaluate a different route from the one FastAPI dispatched.
Most deployments are not affected. The bypass is blocked by any upstream layer that validates or normalizes Host, such as:
server_name allowlistsLiteLLM Cloud customers are not affected.
Fixed in 1.84.0. Upgrade to 1.84.0 or later. No configuration change is required.
If upgrading is not immediately possible, place the proxy behind an upstream component that validates or normalizes the Host header before forwarding (a CDN/WAF, a reverse proxy with explicit server_name allowlists, or a cloud load balancer with host-based routing rules), or otherwise restrict network access to the proxy listener.
v1.84.0Discovery Credit: Le The Thang (KCSC) and Kim Ngoc Chung (One Mount Group)
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