CVE-2026-1299

Publication date 23 January 2026

Last updated 6 July 2026

Ubuntu priority

Medium

Why this priority?

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".

Status

Package Ubuntu Release Status
pypy3 26.10 stonking
Needs evaluation
26.04 LTS resolute
Needs evaluation
25.10 questing Ignored end of life, was needs-triage
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
python2.7 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation
python3.4 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
14.04 LTS trusty
Needs evaluation
python3.5 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation
python3.6 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Needs evaluation
python3.7 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Needs evaluation
python3.8 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
python3.9 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Needs evaluation
python3.10 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Fixed in 3.10.12-1~22.04.16
python3.11 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Needs evaluation
python3.12 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble
Fixed in 3.12.3-1ubuntu0.15
22.04 LTS jammy Not in release
python3.13 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Ignored end of life, was needs-triage
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
python3.14 26.10 stonking
Fixed in 3.14.3-1
26.04 LTS resolute
Fixed in 3.14.3-1
25.10 questing Ignored end of life, was needs-triage
24.04 LTS noble Not in release
22.04 LTS jammy Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
python3.11
python3.12
python3.13
python3.14

Severity score breakdown

CVSS version: CVSS v4.0

Base score 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

References

Related Ubuntu Security Notices (USN)

Other references

Access our resources on patching vulnerabilities