USN-8018-2

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.

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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...