CVE-2025-11468

MEDIUM

CPython HTTP Header Injection via Email Header Folding

Title source: llm
STIX 2.1

Description

When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.

References (9)

Core 9
Core References
Issue Tracking issue-tracking
https://github.com/python/cpython/issues/143935

Scores

CVSS v4 5.7
EPSS 0.0055
EPSS Percentile 42.9%
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-93
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