CVE-2026-109518

NameCVE-2026-109518
DescriptionOn 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
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4880-1, DSA-6607-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
apt (PTS)bookworm2.6.1vulnerable
bookworm (security)2.6.2fixed
trixie3.0.3vulnerable
trixie (security)3.0.4fixed
forky3.3.6fixed
sid3.3.7fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
aptsourcebookworm2.6.2DLA-4880-1
aptsourcetrixie3.0.4DSA-6607-1
aptsource(unstable)3.3.6

Notes

https://lists.debian.org/deity/2026/11/msg00005.html
Fixed by: https://salsa.debian.org/apt-team/apt/-/commit/5af16a8ad0f155233dfb10b7c92ad1903112ef79 (3.3.6)

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