---
id: CVE-2026-94422
title: >-
  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
summary: >-
  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 malic…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-290
vendor: Fedora
product: xdg-dbus-proxy
affected:
  - xdg-dbus-proxy < 0.1.9
  - xdg-dbus-proxy < 0.1.9
  - xdg-dbus-proxy (all versions)
  - xdg-dbus-proxy (all versions)
published: '2026-10-02'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T14:17:12.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-94422'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-94422'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2542235'
    label: secalert@redhat.com
  - url: >-
      https://github.com/flatpak/xdg-dbus-proxy/commit/e4465a0dfe96da3b39929a30a1ac3a22b16223e3
    label: secalert@redhat.com
  - url: >-
      https://github.com/flatpak/xdg-dbus-proxy/commit/e5702fca4dba9600721921fbca2dbc39dc5ca400
    label: secalert@redhat.com
  - url: >-
      https://github.com/flatpak/xdg-dbus-proxy/commit/fc027f759316fb2a6c45648200b6f100202eb84e
    label: secalert@redhat.com
  - url: >-
      https://github.com/flatpak/xdg-dbus-proxy/security/advisories/GHSA-2cgv-pwcq-wvpq
    label: secalert@redhat.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-02T14:20:32.574Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.