CVE-2026-94422
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-290 |
| Published | Oct 2, 2026 |
| Last Updated | Oct 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
Fedora / Fedora
0 < 0.1.9
Red Hat / Red Hat Enterprise Linux 9
All versions affected Red Hat / Red Hat Enterprise Linux 10
All versions affected References
access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-94422 github.com: https://github.com/flatpak/xdg-dbus-proxy/security/advisories/GHSA-2cgv-pwcq-wvpq github.com: https://github.com/flatpak/xdg-dbus-proxy/commit/e5702fca4dba9600721921fbca2dbc39dc5ca400 github.com: https://github.com/flatpak/xdg-dbus-proxy/commit/fc027f759316fb2a6c45648200b6f100202eb84e github.com: https://github.com/flatpak/xdg-dbus-proxy/commit/e4465a0dfe96da3b39929a30a1ac3a22b16223e3 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2542235 openwall.com: http://www.openwall.com/lists/oss-security/2026/09/23/5
Credits
🔍 refi64