U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-0865 Detail

Description

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


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  Python Software Foundation
CVSS-B 5.9 MEDIUM
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

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://github.com/python/cpython/commit/22e4d55285cee52bc4dbe061324e5f30bd4dee58 Python Software Foundation
https://github.com/python/cpython/commit/23e3c0ae867cca0130e441e776c9955b9027c510 Python Software Foundation
https://github.com/python/cpython/commit/2f840249550e082dc351743f474ba56da10478d2 Python Software Foundation
https://github.com/python/cpython/commit/4802b96a2cde58570c24c13ef3289490980961c5 Python Software Foundation
https://github.com/python/cpython/commit/e4846a93ac07a8ae9aa18203af0dd13d6e7a6995 Python Software Foundation
https://github.com/python/cpython/commit/f7fceed79ca1bceae8dbe5ba5bc8928564da7211 Python Software Foundation
https://github.com/python/cpython/issues/143916 Python Software Foundation
https://github.com/python/cpython/pull/143917 Python Software Foundation
https://mail.python.org/archives/list/[email protected]/thread/BJ6QPHNSHJTS3A7CFV6IBMCAP2DWRVNT/ Python Software Foundation

Weakness Enumeration

CWE-ID CWE Name Source
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') Python Software Foundation  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-0865
NVD Published Date:
01/20/2026
NVD Last Modified:
01/20/2026
Source:
Python Software Foundation