CVE-2026-1299
EPSS 0.05%email BytesGenerator header injection due to unquoted newlines
Published: 1/23/2026Modified: 5/16/2026
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".
Affected packages (8)
- Bitnami/libpythonfrom 0, < 3.10.20, >= 3.11.0, < 3.11.15, >= 3.12.0, < 3.12.13, >= 3.13.0, < 3.13.12, >= 3.14.0, < 3.14.3
- Bitnami/pythonfrom 0, < 3.10.20, >= 3.11.0, < 3.11.15, >= 3.12.0, < 3.12.13, >= 3.13.0, < 3.13.12, >= 3.14.0, < 3.14.3
- Bitnami/python-minfrom 0, < 3.10.20, >= 3.11.0, < 3.11.15, >= 3.12.0, < 3.12.13, >= 3.13.0, < 3.13.12, >= 3.14.0, < 3.14.3
- Debian/pypy3from 0
- Debian/python3.11from 0, < 3.11.2-6+deb12u7
- Debian/python3.13from 0, < 3.13.5-2+deb13u1
- Debian/python3.14from 0, < 3.14.3-1
- Debian/python3.9from 0, < 3.9.2-1+deb11u5
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
References (12)
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-1299
- WEBhttps://cve.org/CVERecord?id=CVE-2024-6923
- WEBhttps://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413
- WEBhttps://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8
- WEBhttps://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9
- WEBhttps://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4
- WEBhttps://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36
- WEBhttps://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831a
- WEBhttps://github.com/python/cpython/issues/144125
- WEBhttps://github.com/python/cpython/pull/144126
- WEBhttps://mail.python.org/archives/list/[email protected]/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/
- WEBhttps://nvd.nist.gov/vuln/detail/CVE-2026-1299