Skip to content
Sign in
6.0 Medium

CVE-2026-1299 The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when …

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 products and versions

Product Affected versions Fixed in
CPython 3.15 3.15.0a1 → < 3.15.0a6 3.15.0a6
CPython 3.14 3.14.0 → < 3.14.3 3.14.3
CPython 3.13 3.13.0 → < 3.13.12 3.13.12
CPython 3.12 3.12.0 → < 3.12.13 3.12.13
CPython 3.11 3.11.0 → < 3.11.15 3.11.15
CPython 3.10 earliest → < 3.10.20 3.10.20

Other CVEs of CPython

The 80 CVEs of CPython →
CVE-2026-119170 Regression in FIPS enforcement of hash algorithms affecting only Python 3.14.10 8.2 High CVE-2026-116566 socket.getaddrinfo() previously accepted null bytes within *host* and *port* parameters which can cause the values to be… 5.3 Medium CVE-2026-103995 Lenient parsing of integers for response body and chunk framing 2.0 Low CVE-2026-115557 Python has added a denylist for known compromised certificates to the "ssl" module to ensure user safety even without… 9.4 Critical
Track this CVE