CVE-2025-11468 MEDIUM

CVE-2025-11468: Folding email comments of unfoldable characters doesn't preserve parenthesis

Vendor Python Software Foundation
Product CPython
Published January 20, 2026
Last update March 3, 2026

CVSS base score

5.7/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 20, 2026 CVE published
March 3, 2026 Record updated