Description
User-controlled header names and values containing newlines can allow injecting HTTP headers.
References (15)
Core 15
Core References
Various Sources vendor-advisory
https://mail.python.org/archives/list/[email protected]/thread/BJ6QPHNSHJTS3A7CFV6IBMCAP2DWRVNT/
Issue Tracking issue-tracking
https://github.com/python/cpython/issues/143916
Issue Tracking patch
https://github.com/python/cpython/pull/143917
Scores
CVSS v4
5.9
EPSS
0.0013
EPSS Percentile
32.3%
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
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-74
Status
published
Products (6)
Python Software Foundation/CPython
< 3.10.20
Python Software Foundation/CPython
3.11.0 - 3.11.15
Python Software Foundation/CPython
3.12.0 - 3.12.13
Python Software Foundation/CPython
3.13.0 - 3.13.12
Python Software Foundation/CPython
3.14.0 - 3.14.3
Python Software Foundation/CPython
3.15.0a1 - 3.15.0a6
Published
Jan 20, 2026
Tracked Since
Feb 18, 2026