CVE-2025-11468

Folding email comments of unfoldable characters doesn't preserve parenthesis

Published Jan 20, 2026 CVSS 4.0 · 5.7 Medium EPSS < 1% KEV · Not listed
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.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4455-1 python3.9 security update
Ubuntu USN Ubuntu USN USN-8018-1 Python vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-93
Type Values Removed Values Added
Weaknesses CWE-140
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython
Type Values Removed Values Added
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.
Title Folding email comments of unfoldable characters doesn't preserve parenthesis
References
Metrics cvssV4_0

{'score': 5.7, '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'}

Weaknesses
  • CWE-140

    Improper Neutralization of Delimiters

  • CWE-93

    Improper Neutralization of CRLF Sequences ('CRLF Injection')

Sources

Status
PUBLISHED
Assigner
PSF
Published
Updated
Mar 3, 2026, 2:41 PM
Reserved
Oct 7, 2025, 9:04 PM
Status
Deferred
Published
Jan 20, 2026, 10:15 PM
Modified
Jun 17, 2026, 8:30 AM
Severity
Moderate
Public date
Jan 20, 2026, 9:09 PM