Description
An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass the intended message filtering on the D-Bus session bus by setting a reply serial number on non-reply messages. A malicious or compromised Flatpak app could use this to achieve arbitrary code execution outside its sandbox. xdg-dbus-proxy was designed to be part of the sandbox boundary for Flatpak, but it is released as a separate project and is sometimes used by other app frameworks such as Firejail.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | xdg-dbus-proxy | < 0.1.9 | 0.1.9 |
| Fedora | Fedora | < 0.1.9 | 0.1.9 |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
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 | xdg-dbus-proxy | 0.1.9-1 | — |
| Debian 13 | xdg-dbus-proxy | 0.1.6-1+deb13u3 | — |
| Debian 12 | xdg-dbus-proxy | 0.1.4-3+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | xdg-dbus-proxy | No fix yet | — |
| Ubuntu 26.04 LTS | xdg-dbus-proxy | No fix yet | — |
| Ubuntu 24.04 LTS | xdg-dbus-proxy | No fix yet | — |
| Ubuntu 22.04 LTS | xdg-dbus-proxy | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | xdg-dbus-proxy | No fix yet | — |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | xdg-dbus-proxy | 0.1.5-4.el10_2.1 | ALSA-2026:90523 |
| AlmaLinux 9 | xdg-dbus-proxy | 0.1.3-1.el9_8.1 | ALSA-2026:90522 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | xdg-dbus-proxy | 0.1.5-4.el10_2.1 | RLSA-2026:90523 |
| Rocky Linux 9 | xdg-dbus-proxy | 0.1.3-1.el9_8.1 | RLSA-2026:98530, RLSA-2026:90522 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xdg-dbus-proxy | 0.1.9-1.1 | openSUSE-SU-2026:11913-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xdg-dbus-proxy | 0.1.9-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | xdg-dbus-proxy | 0.1.9-1.amzn2023.0.1 | ALAS2023-2026-3185 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | xdg-dbus-proxy | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | xdg-dbus-proxy | 0.1.5-4.el10_2.1 | ELSA-2026-90523 |
| Oracle Linux 9 | xdg-dbus-proxy | 0.1.3-1.el9_8.1 | ELSA-2026-90522 |
Advisories 10
- RLSA-2026:98530 Important: xdg-dbus-proxy security update Rocky Linux Security Advisories · Nov 12, 2026
- WID-SEC-2026-4172 Red Hat Enterprise Linux (xdg-dbus-proxy): Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Nov 11, 2026
- RLSA-2026:90522 Important: xdg-dbus-proxy security update Rocky Linux Security Advisories · Oct 29, 2026
- RLSA-2026:90523 Important: xdg-dbus-proxy security update Rocky Linux Security Advisories · Oct 29, 2026
- ALSA-2026:90522 Important: xdg-dbus-proxy security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:90523 Important: xdg-dbus-proxy security update AlmaLinux Security Advisories · Oct 29, 2026
- ELSA-2026-90523 Important: xdg-dbus-proxy security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 26, 2026
- ELSA-2026-90522 Important: xdg-dbus-proxy security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 26, 2026
- ALAS2023-2026-3185 Important: xdg-dbus-proxy security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- openSUSE-SU-2026:11913-1 xdg-dbus-proxy-0.1.9-1.1 on GA media SUSE / openSUSE Security Updates · Sep 29, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-94422 vendor-advisory
- https://github.com/flatpak/xdg-dbus-proxy/security/advisories/GHSA-2cgv-pwcq-wvpq third-party-advisory
- https://github.com/flatpak/xdg-dbus-proxy/commit/e5702fca4dba9600721921fbca2dbc39dc5ca400 patch
- https://github.com/flatpak/xdg-dbus-proxy/commit/fc027f759316fb2a6c45648200b6f100202eb84e patch
- https://github.com/flatpak/xdg-dbus-proxy/commit/e4465a0dfe96da3b39929a30a1ac3a22b16223e3 patch
- https://bugzilla.redhat.com/show_bug.cgi?id=2542235 issue-tracking