Summary
USN-8018-1 fixed vulnerabilities in python3. That update introduced
regressions. The patches for CVE-2025-15366 and CVE-2025-15367 caused
behavior regressions in IMAP and POP3 handling, which upstream chose to
avoid by not backporting them. Additionally, the patch for CVE-2026-0865
incorrectly rejected horizontal tabs in wsgiref headers. This update fixes
these problems.
We apologize for the inconvenience.
Original advisory details:
Denis Ledoux discovered that Python incorrectly parsed email message
headers. An attacker could possibly use this issue to inject arbitrary
headers into email messages. This issue only affected python3.6,
python3.7, python3.8, python3.9, python3.10, python3.11, python3.12,
python3.13, and python3.14 packages. (CVE-2025-11468)
Jacob Walls, Shai Berger, and Natalia Bidart discovered that Python
inefficiently parsed XML input with quadratic complexity. An attacker
could possibly use this issue to cause a denial of service.
(CVE-2025-12084)
It was discovered that Python incorrectly parsed malicious plist files. An
attacker could possibly use this issue to cause Python to use excessive
resources, leading to a denial of service. This issue only affected
python3.5, python3.6, python3.7, python3.8, python3.9, python3.10,
python3.11, python3.12, python3.13, and python3.14 packages.
(CVE-2025-13837)
Omar Hasan discovered that Python incorrectly parsed URL mediatypes. An
attacker could possibly use this issue to inject arbitrary HTTP headers.
(CVE-2025-15282)
Omar Hasan discovered that Python incorrectly parsed malicious IMAP
inputs. An attacker could possibly use this issue to inject arbitrary
IMAP commands. (CVE-2025-15366)
Omar Hasan discovered that Python incorrectly parsed malicious POP3
inputs. An attacker could possibly use this issue to inject arbitrary
POP3 commands. (CVE-2025-15367)
Omar Hasan discovered that Python incorrectly parsed malicious HTTP cookie
headers. An attacker could possibly use this issue to inject arbitrary
HTTP headers. (CVE-2026-0672)
Omar Hasan discovered that Python incorrectly parsed malicious HTTP header
names and values. An attacker could possibly use this issue to inject
arbitrary HTTP headers. (CVE-2026-0865)
Fixed packages 13
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | python3.10 | 3.10.12-1~22.04.15 |
| Ubuntu · 24.04 LTS 24.04:LTS | python3.12 | 3.12.3-1ubuntu0.12 |
| Ubuntu · 25.10 | python3.13 | 3.13.7-1ubuntu0.4 |
| Ubuntu · 25.10 | python3.14 | 3.14.0-1ubuntu0.3 |
| Ubuntu · Pro 14.04 LTS Pro:14.04:LTS | python3.4 | 3.4.3-1ubuntu1~14.04.7+esm20 |
| Ubuntu · Pro 14.04 LTS Pro:14.04:LTS | python3.5 | 3.5.2-2ubuntu0~16.04.4~14.04.1+esm10 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | python3.5 | 3.5.2-2ubuntu0~16.04.13+esm22 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | python3.6 | 3.6.9-1~18.04ubuntu1.13+esm9 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | python3.7 | 3.7.5-2ubuntu1~18.04.2+esm10 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | python3.8 | 3.8.0-3ubuntu1~18.04.2+esm10 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | python3.8 | 3.8.10-0ubuntu1~20.04.18+esm6 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | python3.9 | 3.9.5-3ubuntu0~20.04.1+esm10 |
| Ubuntu · Pro 22.04 LTS Pro:22.04:LTS | python3.11 | 3.11.0~rc1-1~22.04.1~esm9 |