CVE-2026-1299CWE-93

email BytesGenerator header injection due to unquoted newlines

Medium · published January 23, 2026

CVSS v4.0
6.0
EPSS
1%
Percentile
46.6
In the wild
Unconfirmed
What it is

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".

The record
Technical detail
CVSS v4.0
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
EPSS
0.00573 · 46.6th percentile
Weakness
CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')
Published
2026-01-23T16:27Z
EPSS history
Timeline
  • 23 JAN 16:27Z
    email BytesGenerator header injection due to unquoted newlines
    cvelistv5