Uncaught Exception in granian - CVE-2026-42545
Published: July 20, 2026
Vulnerability identifier: #VU138774
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-42545
CWE-ID: CWE-248
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to Granian aborts a worker process if a WSGI application returns an invalid HTTP response header name or value. The WSGI response conversion path uses .unwrap() on both the header name and header value constructors, so malformed output from the application becomes a process abort instead of a handled error. A remote attacker can trigger an uncaught exception and perform a denial of service (DoS) attack.
Affected software
granian
How to mitigate CVE-2026-42545
Install updates from vendor's website.
granian - update to 2.7.4