Millions of AI agents imperiled by critical vulnerability in open source package

Researchers found a critical Starlette flaw, dubbed BadHost, that can bypass path-based authorization using the HTTP Host header.

The issue affects Starlette versions before 1.0.1 and can impact FastAPI apps plus tooling like MCP servers, vLLM, LiteLLM, and TGI.

Because these services often expose sensitive data and credentials, the bug creates a broad attack surface for theft and unauthorized access.

Security teams should upgrade Starlette immediately and review any exposed ASGI or AI service endpoints.