Description
In Flatpak before 1.18.1, the revokefs writer, used by the flatpak-system-helper to receive repository data from unprivileged callers, validated file paths by rejecting literal .. components but did not prevent symlink traversal. A malicious local user in an active local session could obtain two revokefs sessions via the system helper, create a symlink in one session pointing into the other session's directory, and retain a file descriptor through that symlink. This allowed the attacker to modify files belonging to a different revokefs session after they had been validated and imported by the system helper. In particular, an attacker could use this to tamper with ostree commit objects in the system repository after they passed signature verification, enabling root-controlled file writes to attacker-chosen paths and local root privilege escalation.
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~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 | — |
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-2026:98595, RLSA-2026:80498 |
| Rocky Linux 10 | flatpak-libs +3 | 1.18.0-2.el10_3.4 | RLSA-2026:98595 |
| Rocky Linux 9 | flatpak | 1.12.9-4.el9_8.4 | RLSA-2026:98490, RLSA-2026:80497 |
| Rocky Linux 9 | flatpak-libs +3 | 1.12.9-6.el9_9.5 | RLSA-2026:98490 |
| 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 |
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 19
- RLSA-2026:98595 Important: flatpak security update Rocky Linux Security Advisories · Nov 13, 2026
- RLSA-2026:98490 Important: flatpak security update Rocky Linux Security Advisories · Nov 13, 2026
- 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-2026-80497 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
- ELSA-2026-80498 Important: flatpak security update (Oracle Linux 10) 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