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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Flatpak | Flatpak | < 1.18.1 | 1.18.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | flatpak | 1.18.1-1 | — |
| Debian 13 | flatpak | 1.16.6-1~deb13u3 | — |
| Debian 12 | flatpak | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | flatpak | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | flatpak | No fix yet | — |
| Ubuntu Pro 22.04 LTS | flatpak | No fix yet | — |
| Ubuntu Pro 20.04 LTS | flatpak | No fix yet | — |
| Ubuntu Pro 18.04 LTS | flatpak | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | flatpak +4 | 1.16.0-9.el10_2.4 | RHSA-2026:80498 |
| RHEL 9 | flatpak +4 | 1.12.9-4.el9_8.4 | RHSA-2026:80497 |
| RHEL 8 | flatpak +4 | 1.12.9-7.el8_10 | RHSA-2026:80687 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | flatpak +4 | 1.16.0-9.el10_2.4 | ALSA-2026:80498 |
| AlmaLinux 9 | flatpak +4 | 1.12.9-4.el9_8.4 | ALSA-2026:80497 |
| AlmaLinux 8 | flatpak +4 | 1.12.9-7.el8_10 | ALSA-2026:80687 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | flatpak | 1.16.0-9.el10_2.4 | RLSA-2026:80498 |
| Rocky Linux 9 | flatpak | 1.12.9-4.el9_8.4 | RLSA-2026:80497 |
| Rocky Linux 8 | flatpak | 1.12.9-7.el8_10 | RLSA-2026:80687 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES 15 SP6 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
| SLES 12 SP5 | flatpak | 1.4.2-3.15.1 | SUSE-SU-2026:4610-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | flatpak | 1.16.6-150600.3.12.1 | SUSE-SU-2026:4944-1 |
| SLES for SAP 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
| SLE HPC 15 SP5 | flatpak | 1.16.6-150500.3.21.1 | SUSE-SU-2026:5127-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | flatpak +5 | 1.18.1-1.amzn2023 | ALAS2023-2026-3143 |
| Amazon Linux 2 | flatpak +2 | 1.0.9-10.amzn2.0.8 | ALAS2-2026-3959 |
| Amazon Linux 2 | flatpak-builder | 1.0.0-10.amzn2.0.8 | ALAS2-2026-3959 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | flatpak +4 | 1.16.0-9.el10_2.4 | ELSA-2026-80498 |
| Oracle Linux 9 | flatpak +4 | 1.12.9-4.el9_8.4 | ELSA-2026-80497 |
| Oracle Linux 8 | flatpak +4 | 1.12.9-7.el8_10 | ELSA-2026-80687 |
Advisories 18
- WID-SEC-2026-3861 Red Hat Enterprise Linux (flatpak): Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- SUSE-SU-2026:5127-1 Security update for flatpak SUSE / openSUSE Security Updates · Nov 7, 2026
- SUSE-SU-2026:4944-1 Security update for flatpak SUSE / openSUSE Security Updates · Oct 31, 2026
- ALSA-2026:80497 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:80498 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:80687 Important: flatpak security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:80497 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2026:80498 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RHSA-2026:80687 Red Hat Security Advisory: flatpak security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- RLSA-2026:80497 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- RLSA-2026:80498 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- RLSA-2026:80687 Important: flatpak security update Rocky Linux Security Advisories · Oct 13, 2026
- ELSA-2026-80498 Important: flatpak security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
- ELSA-2026-80497 Important: flatpak security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
- ELSA-2026-80687 Important: flatpak security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 11, 2026
- SUSE-SU-2026:4610-1 Security update for flatpak SUSE / openSUSE Security Updates · Oct 10, 2026
- ALAS2023-2026-3143 Important: flatpak security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 30, 2026
- ALAS2-2026-3959 Important: flatpak security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 30, 2026