The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
History

Mon, 26 Jan 2026 14:45:00 +0000


Mon, 26 Jan 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython

Fri, 23 Jan 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Fri, 23 Jan 2026 16:45:00 +0000

Type Values Removed Values Added
Description The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
Title email BytesGenerator header injection due to unquoted newlines
Weaknesses CWE-93
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: PSF

Published: 2026-01-23T16:27:13.346Z

Updated: 2026-01-26T14:20:21.976Z

Reserved: 2026-01-21T18:30:52.594Z

Link: CVE-2026-1299

cve-icon Vulnrichment

Updated: 2026-01-23T16:56:16.248Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-01-23T17:16:12.977

Modified: 2026-01-26T15:16:07.237

Link: CVE-2026-1299

cve-icon Redhat

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