USN-8996-1: APT vulnerability

Q: What attacker position is required to exploit this issue?

An attacker must be able to act on-path between APT and the package download source, so they can interfere with redirects and retried package downloads.

Q: What is the potential impact if exploitation succeeds?

APT may be tricked into installing an unverified package. This could lead to remote code execution with root privileges.

Published Nov 4, 2026

Updated

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.

Affected Software

24 affected componentsFixes available

All of the following

ubuntu/apt<3.3.3ubuntu0.1

3.3.3ubuntu0.1

Ubuntu Ubuntu=26.10

All of the following

ubuntu/apt<3.2.1ubuntu0.1

3.2.1ubuntu0.1

Ubuntu Ubuntu=26.04

All of the following

ubuntu/apt<2.8.4ubuntu0.1

2.8.4ubuntu0.1

Ubuntu Ubuntu=24.04

All of the following

ubuntu/apt<2.4.15ubuntu0.1

2.4.15ubuntu0.1

Ubuntu Ubuntu=22.04

All of the following

ubuntu/apt<Ubuntu Pro

Ubuntu Pro

Ubuntu Ubuntu=20.04

All of the following

ubuntu/apt<Ubuntu Pro

Ubuntu Pro

Ubuntu Ubuntu=18.04

All of the following

ubuntu/apt<Ubuntu Pro

Ubuntu Pro

Ubuntu Ubuntu=16.04

All of the following

ubuntu/apt<Ubuntu Pro

Ubuntu Pro

Ubuntu Ubuntu=14.04

ubuntu/apt<1.0.1ubuntu2.24+esm4

1.0.1ubuntu2.24+esm4

ubuntu/apt<1.2.36+esm1

1.2.36+esm1

ubuntu/apt<1.6.19+esm1

1.6.19+esm1

ubuntu/apt<2.0.12+esm1

2.0.12+esm1

ubuntu/apt<2.4.15ubuntu0.1

2.4.15ubuntu0.1

ubuntu/apt<2.8.4ubuntu0.1

2.8.4ubuntu0.1

ubuntu/apt<3.3.3ubuntu0.1

3.3.3ubuntu0.1

ubuntu/apt<3.2.1ubuntu0.1

3.2.1ubuntu0.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 3.3.3ubuntu0.1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 3.2.1ubuntu0.1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 2.8.4ubuntu0.1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 2.4.15ubuntu0.1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in Ubuntu Pro
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 1.0.1ubuntu2.24+esm4
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 1.2.36+esm1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 1.6.19+esm1
Upgrade
Upgrade ubuntu/apt to a version that resolves this vulnerability.
Fixed in 2.0.12+esm1

Event History

Nov 4, 2026

Advisory Published

via Ubuntu·12:00 AM

Data Sourced

via Ubuntu·12:00 AM

DescriptionAffected Software

Advisory Published

via OSV·01:37 PM

Data Sourced

via OSV·01:37 PM

DescriptionAffected Software

Child vulnerabilities

Contains the following vulnerabilities.

Frequently Asked Questions

What attacker position is required to exploit this issue?

An attacker must be able to act on-path between APT and the package download source, so they can interfere with redirects and retried package downloads.

What is the potential impact if exploitation succeeds?

APT may be tricked into installing an unverified package. This could lead to remote code execution with root privileges.

USN-8996-1: APT vulnerability

Affected Software

Remediation

Event History

Child vulnerabilities

Frequently Asked Questions

What attacker position is required to exploit this issue?

What is the potential impact if exploitation succeeds?

Company

Resources

Contact

Frequently Asked Questions

What attacker position is required to exploit this issue?

What is the potential impact if exploitation succeeds?