CVE-2025-15282

Severity CVSS v4.0:

MEDIUM

Type:

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Publication date:

20/01/2026

Last modified:

26/01/2026

Description

User-controlled data URLs parsed by urllib.request.DataHandler allow injecting headers through newlines in the data URL mediatype.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 6.00 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): Present
Privileges Required (PR): Low
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): High
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): Low
Availability (SA): None

Base Score 4.0

6.00

Severity 4.0

MEDIUM

References to Advisories, Solutions, and Tools

https://github.com/python/cpython/commit/05356b1cc153108aaf27f3b72ce438af4aa218c0
https://github.com/python/cpython/commit/34d76b00dabde81a793bd06dd8ecb057838c4b38
https://github.com/python/cpython/commit/3f396ca9d7bbe2a50ea6b8c9b27c0082884d9f80
https://github.com/python/cpython/commit/4ed11d3cd288e6b90196a15c5a825a45d318fe47
https://github.com/python/cpython/commit/a35ca3be5842505dab74dc0b90b89cde0405017a
https://github.com/python/cpython/commit/f25509e78e8be6ea73c811ac2b8c928c28841b9f
https://github.com/python/cpython/issues/143925
https://github.com/python/cpython/pull/143926
https://mail.python.org/archives/list/security-announce@python.org/thread/X66HL7SISGJT33J53OHXMZT4DFLMHVKF/