When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages. Patch rejects all control characters within cookie names, values, and parameters.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Python
  • Cpython

No data.

No data.

References
Link Providers
https://github.com/python/cpython/commit/95746b3a13a985787ef53b977129041971ed7f70 cve-icon cve-icon
https://github.com/python/cpython/issues/143919 cve-icon cve-icon cve-icon
https://github.com/python/cpython/pull/143920 cve-icon cve-icon cve-icon
https://mail.python.org/archives/list/security-announce@python.org/thread/6VFLQQEIX673KXKFUZXCUNE5AZOGZ45M/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-0672 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-0672 cve-icon
History

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

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/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 22:45:00 +0000

Type Values Removed Values Added
References

Tue, 20 Jan 2026 22:15:00 +0000

Type Values Removed Values Added
Description User-controlled cookie values and parameters can allow injecting HTTP headers. Fix rejects all control characters within cookie names, values, and parameters. When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages. Patch rejects all control characters within cookie names, values, and parameters.
References

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

Type Values Removed Values Added
Description User-controlled cookie values and parameters can allow injecting HTTP headers. Fix rejects all control characters within cookie names, values, and parameters.
Title Header injection in http.cookies.Morsel
Weaknesses CWE-93
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: PSF

Published:

Updated: 2026-01-21T16:14:06.341Z

Reserved: 2026-01-07T17:08:45.326Z

Link: CVE-2026-0672

cve-icon Vulnrichment

Updated: 2026-01-21T15:48:28.463Z

cve-icon NVD

Status : Received

Published: 2026-01-20T22:15:52.680

Modified: 2026-01-20T23:16:05.833

Link: CVE-2026-0672

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-01-20T21:52:33Z

Links: CVE-2026-0672 - Bugzilla