User-controlled header names and values containing newlines can allow injecting HTTP headers.
History

Thu, 22 Jan 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N'}

threat_severity

Moderate


Wed, 21 Jan 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 21 Jan 2026 11:30:00 +0000

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython

Tue, 20 Jan 2026 23:15:00 +0000


Tue, 20 Jan 2026 22:45:00 +0000


Tue, 20 Jan 2026 21:45:00 +0000

Type Values Removed Values Added
Description User-controlled header names and values containing newlines can allow injecting HTTP headers.
Title wsgiref.headers.Headers allows header newline injection
Weaknesses CWE-74
References
Metrics cvssV4_0

{'score': 5.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: PSF

Published: 2026-01-20T21:26:15.274Z

Updated: 2026-01-21T16:14:52.038Z

Reserved: 2026-01-12T16:07:56.781Z

Link: CVE-2026-0865

cve-icon Vulnrichment

Updated: 2026-01-21T15:48:38.269Z

cve-icon NVD

Status : Received

Published: 2026-01-20T22:15:52.800

Modified: 2026-01-20T23:16:05.933

Link: CVE-2026-0865

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-01-20T21:26:15Z

Links: CVE-2026-0865 - Bugzilla