CVE-2026-0672
cpython: Header injection in http.cookies.Morsel in Python
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 21, 2026
Updated · August 25, 2026
Description
An injection flaw has been discovered in Python. 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.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 4.8CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N
CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')