| Name | CVE-2026-90616 |
| Description | 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-6432-1 |
| Debian Bugs | 1144130 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| flatpak (PTS) | bookworm, bookworm (security) | 1.14.10-1~deb12u2 | vulnerable |
| trixie (security), trixie | 1.16.6-1~deb13u2 | fixed | |
| forky, sid | 1.18.2-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| flatpak | source | trixie | 1.16.6-1~deb13u2 | DSA-6432-1 | ||
| flatpak | source | (unstable) | 1.18.1-1 | 1144130 |
https://github.com/flatpak/flatpak/security/advisories/GHSA-8688-9x26-hhxj
Fixed by: https://github.com/flatpak/flatpak/commit/478072972056d2d15c768c246f80abdf83cf0e5e (1.18.1)
Additional tests: https://github.com/flatpak/flatpak/commit/9d26ea5f1e7c8fb43225668a96289d15c62ad6cd (1.18.1)
Additional tests: https://github.com/flatpak/flatpak/commit/01624446aa752184acbe74f9af3b709b7b6728c7 (1.18.1)
Fixed by: https://github.com/flatpak/flatpak/commit/afdd4a156549cdfa26d23f2c791e5ed3995fd6da (branch flatpak-1.16.x)
Additional tests: https://github.com/flatpak/flatpak/commit/03a2be6c6844c3ce54c42fca57ffae59cba1a53a (branch flatpak-1.16.x)
Additional tests: https://github.com/flatpak/flatpak/commit/c3c03bfcbad762bd49d9225435bb462899600614 (branch flatpak-1.16.x)
Additional tests: https://github.com/flatpak/flatpak/commit/f9da73e1e9830e134886be5a50e9de9c382379c4 (branch flatpak-1.16.x)
Additional requirement: https://github.com/flatpak/flatpak/commit/3d43a0f5fa602cc3edc557d8ab835030140792b1 (branch flatpak-1.16.x)
Additional requirement: https://github.com/flatpak/flatpak/commit/68c12b9695eee4a94d896f0cf2f388f0d3c63df1 (branch flatpak-1.16.x)