SOURCE-LINKED INTELLIGENCE

GHSA-4xpc-pv4p-pm3w: LiteLLM: Authentication Bypass via Host Header Injection

OSV AI package advisories · observation · Jun 16, 2026 · UTC

### Impact 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: - a CDN or WAF, such as C

Read original source ↗ Open in workspace

recordType

vulnerability

status

active

evidenceStatus

reported

region

Global