Cyber Resilience

CVE-2025-6966

Memory Safety in Ubuntu Python-Apt ≤ 0.9.3.11

Public PoCMemory Safety
Published
05 December 2025
Modified
07 January 2026
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0013 3th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-6966 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Ubuntu Python-Apt. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-11 (Error Handling) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

NULL pointer dereference enables local DoS via application exploitation (crafted file input).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-25475Same product: Debian Debian Linux
CVE-2024-2496Same product: Debian Debian Linux
CVE-2023-6536Same product: Debian Debian Linux
CVE-2023-6356Same product: Debian Debian Linux
CVE-2026-9639Same vendor: Canonical
CVE-2026-23353Shared CWE-476
CVE-2026-31481Shared CWE-476
CVE-2026-22722Shared CWE-476
CVE-2026-60109Shared CWE-476
CVE-2026-23286Shared CWE-476

Affected Assets

ubuntu
python-apt
0.9.3.11, 0.9.3.5, 1.1.0, 1.6.6, 2.0.1 · ≤ 0.9.3.11 · 1.6.0 — 1.6.6 · 2.0.0 — 2.0.1
debian
debian linux
11.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-11 Error Handling
  • SI-7 Software, Firmware, and Information Integrity
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces validation of deb822 file contents (keys) to reject malformed non-UTF-8 data before TagSection.keys() is reached.

prevent

Requires graceful error handling for invalid input so a malformed key produces a controlled failure instead of a NULL dereference crash.

prevent

Verifies integrity of package files prior to processing, reducing the chance that a crafted deb822 file is accepted by python-apt.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References