Description
On a multi-user system, a user with an active local login session could downgrade a system-wide Flatpak app to an older version by removing the app's remote ref via the unprivileged system-helper RemoveLocalRef method, causing the anti-downgrade check to fail to find a reference date. A malicious local user could use this to expose other users of the same system to an app version with unfixed vulnerabilities.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
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~deb13u2 | — |
| 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 | — |
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 |
Advisories 3
- 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
- SUSE-SU-2026:4610-1 Security update for flatpak SUSE / openSUSE Security Updates · Oct 10, 2026