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.
History

Tue, 12 May 2026 22:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Granian: Unauthenticated DoS via WebSocket subprotocol header panic
Weaknesses CWE-20
CWE-248
CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-12T21:46:19.734Z

Reserved: 2026-04-28T16:56:50.191Z

Link: CVE-2026-42544

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-12T22:16:34.467

Modified: 2026-05-12T22:16:34.467

Link: CVE-2026-42544

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-12T23:45:25Z