CVE-2026-0865 Affecting python3.9 package, versions <3.9.5-3ubuntu0~20.04.1+esm9


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.48% (40th percentile)

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  • Snyk IDSNYK-UBUNTU2004-PYTHON39-15051531
  • published6 Feb 2026
  • disclosed20 Jan 2026

Introduced: 20 Jan 2026

CVE-2026-0865  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 python3.9 to version 3.9.5-3ubuntu0~20.04.1+esm9 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python3.9 package and not the python3.9 package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

User-controlled header names and values containing newlines can allow injecting HTTP headers.

CVSS Base Scores

version 3.1