---
id: CVE-2025-6966
title: >-
  NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux
  systems allows a local attacker to cause a denial of service (process crash)
  via a crafted deb822 file with a malformed non-UTF-8 key.
summary: >-
  NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux
  systems allows a local attacker to cause a denial of service (process crash)
  via a crafted deb822 file with a malformed non-UTF-8 key.
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: ubuntu
product: python-apt
affected:
  - python-apt < 0.9.3.11
  - 'python-apt >= 1.6.0, < 1.6.6'
  - 'python-apt >= 2.0.0, < 2.0.1'
  - 'python-apt >= 2.7.0, < 2.7.7'
  - python-apt = 0.9.3.5
  - python-apt = 0.9.3.11
  - python-apt = 1.1.0
  - python-apt = 1.6.6
  - python-apt = 2.0.1
  - python-apt = 2.4.0
  - python-apt = 2.7.7
  - python-apt = 3.0.0
  - debian_linux = 11.0
patched:
  - python-apt 2.7.7
published: '2025-12-05'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T23:10:00.463'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-6966'
references:
  - url: 'https://bugs.launchpad.net/ubuntu/+source/python-apt/+bug/2091865'
    label: security@ubuntu.com
  - url: 'https://lists.debian.org/debian-lts-announce/2025/12/msg00019.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00145
epssPercentile: 0.03127
ingestedAt: '2026-09-25T23:21:16.893Z'
---

## Overview

NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux systems allows a local attacker to cause a denial of service (process crash) via a crafted deb822 file with a malformed non-UTF-8 key.

## Affected

- `python-apt < 0.9.3.11`
- `python-apt >= 1.6.0, < 1.6.6`
- `python-apt >= 2.0.0, < 2.0.1`
- `python-apt >= 2.7.0, < 2.7.7`
- `python-apt = 0.9.3.5`
- `python-apt = 0.9.3.11`
- `python-apt = 1.1.0`
- `python-apt = 1.6.6`
- `python-apt = 2.0.1`
- `python-apt = 2.4.0`
- `python-apt = 2.7.7`
- `python-apt = 3.0.0`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `python-apt 2.7.7`