CVE-2026-42544
Published:May 12, 2026
Updated:May 18, 2026
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.
Affected Packages
granian (CONDA):
Affected version(s) >=1.2.0 <2.7.4Fix Suggestion:
Update to version 2.7.4https://github.com/emmett-framework/granian.git (GITHUB):
Affected version(s) >=v1.2.0 <v2.7.4Fix Suggestion:
Update to version v2.7.4granian (PYTHON):
Affected version(s) >=1.2.0 <2.7.4Fix Suggestion:
Update to version 2.7.4Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.06