Amazon Linux 2 (EOS) Security Advisory: ALAS2-2026-3959
Advisory Released Date: 2026-09-28
Advisory Updated Date: 2026-09-28
In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker-controlled. Missing symlink protection can redirect the directories. Some of these directories are bind-mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox. (CVE-2026-90616)
Affected Packages:
flatpak
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update flatpak or yum update --advisory ALAS2-2026-3959 to update your system.
aarch64:
flatpak-1.0.9-10.amzn2.0.8.aarch64
flatpak-builder-1.0.0-10.amzn2.0.8.aarch64
flatpak-devel-1.0.9-10.amzn2.0.8.aarch64
flatpak-libs-1.0.9-10.amzn2.0.8.aarch64
flatpak-debuginfo-1.0.9-10.amzn2.0.8.aarch64
i686:
flatpak-1.0.9-10.amzn2.0.8.i686
flatpak-builder-1.0.0-10.amzn2.0.8.i686
flatpak-devel-1.0.9-10.amzn2.0.8.i686
flatpak-libs-1.0.9-10.amzn2.0.8.i686
flatpak-debuginfo-1.0.9-10.amzn2.0.8.i686
src:
flatpak-1.0.9-10.amzn2.0.8.src
x86_64:
flatpak-1.0.9-10.amzn2.0.8.x86_64
flatpak-builder-1.0.0-10.amzn2.0.8.x86_64
flatpak-devel-1.0.9-10.amzn2.0.8.x86_64
flatpak-libs-1.0.9-10.amzn2.0.8.x86_64
flatpak-debuginfo-1.0.9-10.amzn2.0.8.x86_64