Vulnerability · Published Nov 4, 2026 · Assigned by canonical
CVE-2026-109518APT RCE via hard link reuse
High 7.7
In plain English
A high-severity security flaw in APT from Debian. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
On Debian, Ubuntu, and derivative Linux distributions, an on-path attacker who can manipulate the HTTP traffic (including a malicious mirror or proxy) between an APT client and an archive server triggered by a package install can trick the client into installing an attacker-controlled unverified package and achieve remote code execution with root privileges. The vulnerability is caused by the reuse of hard links and requires the client to follow redirects and retry the download of package files. It requires the client to have a non-zero Acquire::Retries configuration setting; the value 3 is the default starting with Debian 12 (bookworm) and Ubuntu 22.04 LTS (Jammy Jellyfish), so older releases are unaffected in a default configuration
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | apt | 3.2.1-r0 | ALPINE-CVE-2026-109518 |
| Debian:12 | apt | 2.6.2 | DEBIAN-CVE-2026-109518 |
| Debian:13 | apt | 3.0.4 | DEBIAN-CVE-2026-109518 |
| Debian:14 | apt | 3.3.6 | DEBIAN-CVE-2026-109518 |
| Ubuntu:22.04:LTS | apt | 2.4.15ubuntu0.1 | USN-8996-1 |
| Ubuntu:22.04:LTS | apt | 2.4.15ubuntu0.1 | UBUNTU-CVE-2026-109518 |
| Ubuntu:24.04:LTS | apt | 2.8.4ubuntu0.1 | USN-8996-1 |
| Ubuntu:24.04:LTS | apt | 2.8.4ubuntu0.1 | UBUNTU-CVE-2026-109518 |
| Ubuntu:26.04:LTS | apt | 3.2.1ubuntu0.1 | UBUNTU-CVE-2026-109518 |
| Ubuntu:26.04:LTS | apt | 3.2.1ubuntu0.1 | USN-8996-1 |
| Ubuntu:26.10 | apt | 3.3.3ubuntu0.1 | USN-8996-1 |
| Ubuntu:26.10 | apt | 3.3.3ubuntu0.1 | UBUNTU-CVE-2026-109518 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Debian | APT | 0 – before 1.2.361.4.0 – before 1.4.121.6.0 – before 1.6.191.8.0 – before 1.8.2.41.8.3 – through 1.8.52.0.0 – before 2.0.122.2.0 – before 2.2.52.4.0 – before 2.4.15 |
| Ubuntu | APT | 0 – before 1.0.1ubuntu2.24+esm41.2.0 – before 1.2.36+esm11.6.0 – before 1.6.19+esm12.0.0 – before 2.0.12+esm12.4.0 – before 2.4.15ubuntu0.12.8.0 – before 2.8.4ubuntu0.13.2.0 – before 3.2.1ubuntu0.13.3.0 – before 3.3.3ubuntu0.1 |
Weakness: CWE-62, CWE-367 · 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