CVE-2026-94422
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
- State
- Published
- Severity
- 8.7 High
- Published
- Oct 2, 2026
- Updated
- Oct 24, 2026
- Reserved
- Sep 21, 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | redhat |
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | redhat |
Weaknesses
- CWE-290 Authentication Bypass by Spoofing
Affected Products
| Product | Versions |
|---|---|
xdg-dbus-proxy |
|
FedoraFedora |
|
Red Hat Enterprise Linux 9Red Hat | |
Red Hat Enterprise Linux 10Red Hat |
References
- https://access.redhat.com/security/cve/CVE-2026-94422vendor-advisory
- https://github.com/flatpak/xdg-dbus-proxy/security/advisories/GHSA-2cgv-pwcq-wvpqthird-party-advisory
- https://github.com/flatpak/xdg-dbus-proxy/commit/e5702fca4dba9600721921fbca2dbc39dc5ca400patch
- https://github.com/flatpak/xdg-dbus-proxy/commit/fc027f759316fb2a6c45648200b6f100202eb84epatch
- https://github.com/flatpak/xdg-dbus-proxy/commit/e4465a0dfe96da3b39929a30a1ac3a22b16223e3patch
- https://bugzilla.redhat.com/show_bug.cgi?id=2542235issue-tracking
- http://www.openwall.com/lists/oss-security/2026/09/23/5
- https://lists.debian.org/debian-lts-announce/2026/10/msg00050.html
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.