CVE-2026-42544 — Granian: Unauthenticated DoS via WebSocket subprotocol header panic
Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, Granian aborts a worker process when an unauthenticated client sends a WebSocket upgrade request whos…
Published: 2026-05-12 · CVSS: 7.5 · CVSS 3.1
Granian is a Rust HTTP server for Python applications. From 1.2.0 to 2.7.4, 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 vulnerability is fixed in 2.7.4.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7