CVE Vulnerabilities

CVE-2026-0672

Improper Neutralization of CRLF Sequences ('CRLF Injection')

Published: Jan 20, 2026 | Modified: Jan 26, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
4.8 MODERATE
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N
Ubuntu
MEDIUM
root.io logo minimus.io logo echo.ai logo

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.

Weakness

The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.

Affected Software

NameVendorStart VersionEnd Version
Python3.10Ubuntujammy*
Python3.11Ubuntuesm-apps/jammy*
Python3.11Ubuntujammy*
Python3.12Ubuntunoble*
Python3.13Ubuntuquesting*
Python3.14Ubuntuquesting*
Python3.4Ubuntuesm-infra-legacy/trusty*
Python3.5Ubuntuesm-infra-legacy/trusty*
Python3.5Ubuntuesm-infra/xenial*
Python3.6Ubuntuesm-infra/bionic*
Python3.7Ubuntuesm-apps/bionic*
Python3.8Ubuntuesm-apps/bionic*
Python3.8Ubuntuesm-infra/focal*
Python3.9Ubuntuesm-apps/focal*

Potential Mitigations

References