CVE-2026-42544

CVE-2026-42544 (Granian) affects Granian versions 1.2.0–2.7.4, where an unauthenticated client sending a WebSocket upgrade request with a non-ASCII Sec-WebSocket-Protocol header causes the server to abort the worker in the WebSocket scope construction path, yielding an unauthenticated DoS. The cr...

Granian vulnerable to unauthenticated DoS via WebSocket subprotocol header panic

Summary Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whose Sec-WebSocket-Protocol header contains non-ASCII bytes. The crash happens in Granian's WebSocket scope construction path, before the ASGI application is invoked. This is a single-request...