CVE-2026-1299
email BytesGenerator header injection due to unquoted newlines
- State
- Published
- Severity
- 6.0 Medium
- Published
- Jan 23, 2026
- Updated
- Mar 3, 2026
- Reserved
- Jan 21, 2026
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".
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.0 Medium | 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 | PSF |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
CPythonPython Software Foundation |
|
References
- https://github.com/python/cpython/pull/144126patch
- https://github.com/python/cpython/issues/144125issue-tracking
- https://cve.org/CVERecord?id=CVE-2024-6923related
- https://mail.python.org/archives/list/security-announce@python.org/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/vendor-advisory
- https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413patch
- https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8patch
- https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9patch
- https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4patch
- https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36patch
- https://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831apatch
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.