Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 : APT vulnerability (USN-8996-1)

high Nessus Plugin ID 376527

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 host has packages installed that are affected by a vulnerability as referenced in the USN-8996-1 advisory.

Max Justicz discovered that APT incorrectly handled hard links when encountering redirects and retrying package downloads. A remote on-path attacker could possibly use this issue to trick APT into installing an unverified package and achieve remote code execution with root privileges.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8996-1

Plugin Details

Severity: High

ID: 376527

File Name: ubuntu_USN-8996-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 11/5/2026

Updated: 11/5/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.32

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-109518

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 7.7

Threat Score: 5.2

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:14.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.10, p-cpe:/a:canonical:ubuntu_linux:apt-transport-https, p-cpe:/a:canonical:ubuntu_linux:apt-utils, p-cpe:/a:canonical:ubuntu_linux:apt, p-cpe:/a:canonical:ubuntu_linux:libapt-inst1.5, p-cpe:/a:canonical:ubuntu_linux:libapt-inst2.0, p-cpe:/a:canonical:ubuntu_linux:libapt-pkg4.12, p-cpe:/a:canonical:ubuntu_linux:libapt-pkg5.0, p-cpe:/a:canonical:ubuntu_linux:libapt-pkg6.0, p-cpe:/a:canonical:ubuntu_linux:libapt-pkg6.0t64, p-cpe:/a:canonical:ubuntu_linux:libapt-pkg7.0

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 11/4/2026

Vulnerability Publication Date: 11/4/2026

Reference Information

CVE: CVE-2026-109518

USN: 8996-1