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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-1299 Detail

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".


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  Python Software Foundation
CVSS-B 6.0 MEDIUM
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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://cve.org/CVERecord?id=CVE-2024-6923 Python Software Foundation
https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413 Python Software Foundation
https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8 Python Software Foundation
https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9 Python Software Foundation
https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4 Python Software Foundation
https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36 Python Software Foundation
https://github.com/python/cpython/issues/144125 Python Software Foundation
https://github.com/python/cpython/pull/144126 Python Software Foundation
https://mail.python.org/archives/list/[email protected]/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/ Python Software Foundation

Weakness Enumeration

CWE-ID CWE Name Source
CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection') Python Software Foundation  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-1299
NVD Published Date:
01/23/2026
NVD Last Modified:
01/26/2026
Source:
Python Software Foundation