Vulnerability 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".
Related Weaknesses (CWE)
References
- https://cve.org/CVERecord?id=CVE-2024-6923
- https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc35941
- https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d
- https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb
- https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e
- https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f3
- https://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831
- https://github.com/python/cpython/issues/144125
- https://github.com/python/cpython/pull/144126
- https://mail.python.org/archives/list/[email protected]/thread/6ZZULG
FAQ
What is CVE-2026-1299?
CVE-2026-1299 is a documented vulnerability. 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 serializ...
How severe is CVE-2026-1299?
CVSS scoring is not yet available for CVE-2026-1299. Check NVD for updates.
Is there a patch for CVE-2026-1299?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.