CVE-2026-115917: vLLM: Permissive default CORS origins allow cross-origin requests to the vLLM HTTP server

The OpenAI-compatible server registers Starlette CORSMiddleware with allowed_origins defaulting to ["*"], and performs no authentication unless --api-key (or VLLM_API_KEY) is configured. A web page on any origin can send requests to a vLLM server that the victim’s browser can reach (for example localhost or an internal/VPN address) and read the responses. The default allow_credentials=False blocks cookie-bearing cross-origin requests; because vLLM authenticates with a bearer header rather than cookies, the wildcard still permits untokenized access to an unauthenticated server and read access when the caller already holds a token.