# CVE-2026-94422: xdg-dbus-proxy: An incorrect implementation of message filtering in xdg-dbus-proxy versions before 0.1.9 allows an attacker to bypass...

CVE-2026-94422 is fixed in 3 products on 1 platform, first by RHSA-2026:91626, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-94422
- Priority: High
- CVSS: 8.8 (important)
- EPSS: 0.0050
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | xdg-dbus-proxy Debian 12.15 (bookworm) | 0.1.4-3+deb12u2 | [DEBIAN-CVE-2026-94422](https://patchblox.com/security/data/fix/linux/debian-cve-2026-94422.md) | Sep 23, 2026 |
| Linux | xdg-dbus-proxy Debian 13.5 (trixie) | 0.1.6-1+deb13u3 | [DEBIAN-CVE-2026-94422](https://patchblox.com/security/data/fix/linux/debian-cve-2026-94422.md) | Sep 23, 2026 |
| Linux | xdg-dbus-proxy Debian 14 | 0.1.9-1 | [DEBIAN-CVE-2026-94422](https://patchblox.com/security/data/fix/linux/debian-cve-2026-94422.md) | Sep 23, 2026 |
| Linux | xdg-dbus-proxy Fedora 43 | 0.1.9-1.fc43 | [FEDORA-2026-E1CAC11588](https://patchblox.com/security/data/fix/linux/fedora-2026-e1cac11588.md) | Sep 28, 2026 |
| Linux | xdg-dbus-proxy RHEL 10 | 0.1.5-4.el10_0.1 | [RHSA-2026:91626](https://patchblox.com/security/data/fix/linux/rhsa-2026-91626.md) | Sep 23, 2026 |
| Linux | xdg-dbus-proxy RHEL 9 | 0:0.1.3-1.el9_8.1 | [RHSA-2026:90522](https://patchblox.com/security/data/fix/linux/rhsa-2026-90522.md) | Oct 29, 2026 |
| Linux | xdg-dbus-proxy almalinux 10 | 0.1.5-4.el10_2.1 | [ALSA-2026:90523](https://patchblox.com/security/data/fix/linux/alsa-2026-90523.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy almalinux 9 | 0.1.3-1.el9_8.1 | [ALSA-2026:90522](https://patchblox.com/security/data/fix/linux/alsa-2026-90522.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy amzn 2023 | 0.1.9-1.amzn2023.0.1 | [ALAS2023-2026-3185](https://patchblox.com/security/data/fix/linux/alas2023-2026-3185.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy ol 10 | 0:0.1.5-4.el10_2.1 | [ELSA-2026-90523](https://patchblox.com/security/data/fix/linux/elsa-2026-90523.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy ol 9 | 0:0.1.3-1.el9_8.1 | [ELSA-2026-90522](https://patchblox.com/security/data/fix/linux/elsa-2026-90522.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy rocky 10 | 0:0.1.5-4.el10_2.1 | [RLSA-2026:90523](https://patchblox.com/security/data/fix/linux/rlsa-2026-90523.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy rocky 9 | 0:0.1.3-1.el9_8.1 | [RLSA-2026:90522](https://patchblox.com/security/data/fix/linux/rlsa-2026-90522.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy-debuginfo Fedora 43 | 0.1.9-1.fc43 | [FEDORA-2026-E1CAC11588](https://patchblox.com/security/data/fix/linux/fedora-2026-e1cac11588.md) | Sep 28, 2026 |
| Linux | xdg-dbus-proxy-debuginfo amzn 2023 | 0.1.9-1.amzn2023.0.1 | [ALAS2023-2026-3185](https://patchblox.com/security/data/fix/linux/alas2023-2026-3185.md) | Nov 7, 2026 |
| Linux | xdg-dbus-proxy-debugsource Fedora 43 | 0.1.9-1.fc43 | [FEDORA-2026-E1CAC11588](https://patchblox.com/security/data/fix/linux/fedora-2026-e1cac11588.md) | Sep 28, 2026 |
| Linux | xdg-dbus-proxy-debugsource amzn 2023 | 0.1.9-1.amzn2023.0.1 | [ALAS2023-2026-3185](https://patchblox.com/security/data/fix/linux/alas2023-2026-3185.md) | Nov 7, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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