CVE-2025-6966: Null-pointer dereference in python-apt TagSection.keys()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-12-05 · updated 2026-09-25
Weakness: CWE-476

Description

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 products

Debian Linux: 11.0
Ubuntu Python-Apt: before 0.9.3.11; from 1.6.0 before 1.6.6; from 2.0.0 before 2.0.1; from 2.7.0 before 2.7.7; 0.9.3.5-ubuntu1, 0.9.3.5-ubuntu2, 0.9.3.11, 0.9.3.11-build1, 1.1.0-beta1, 1.1.0-beta1build1 (+33) — fixed in 0.9.3.11, 1.6.6, 2.0.1, 2.7.7

How to fix

Upgrade to a fixed version: Ubuntu Python-Apt 0.9.3.11, 1.6.6, 2.0.1, 2.7.7. Check the vendor advisory for mitigations.

References

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