CVE-2026-94422
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
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.
- Record
CVE-2026-94422- CVSS 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 - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-290
- Updated
- 2026-11-02
EUVDEUVD-2026-91646
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.
- Record
EUVD-2026-91646- CVSS 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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-94422- CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-290
- Updated
- 2026-11-02
OSVALPINE-CVE-2026-94422
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.
- Record
ALPINE-CVE-2026-94422- CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-03
OSV
xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape
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.
- Record
CVE-2026-94422- CVSS 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 - Weakness
- CWE-290
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-94422
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.
- Record
DEBIAN-CVE-2026-94422- CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
Show 12 moreShow less
OSVOESA-2026-4640
xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
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.(CVE-2026-94422)
- Record
OESA-2026-4640- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVOESA-2026-4641
xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
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.(CVE-2026-94422)
- Record
OESA-2026-4641- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVOESA-2026-4642
xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
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.(CVE-2026-94422)
- Record
OESA-2026-4642- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVOESA-2026-4643
xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
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.(CVE-2026-94422)
- Record
OESA-2026-4643- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVRLSA-2026:90522
Important: xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
- xdg-dbus-proxy: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape (CVE-2026-94422)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
RLSA-2026:90522- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVRLSA-2026:90523
Important: xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
- xdg-dbus-proxy: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape (CVE-2026-94422)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
RLSA-2026:90523- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-94422
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.
- Record
UBUNTU-CVE-2026-94422- CVSS 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 - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVALSA-2026:90522 No score
Important: xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
- xdg-dbus-proxy: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape (CVE-2026-94422)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
ALSA-2026:90522- Updated
- 2026-11-02
OSVALSA-2026:90523 No score
Important: xdg-dbus-proxy security update
xdg-dbus-proxy is a filtering proxy for D-Bus connections. It was originally part of the flatpak project, but it has been broken out as a standalone module to facilitate using it in other contexts.
Security Fix(es):
- xdg-dbus-proxy: xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape (CVE-2026-94422)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
- Record
ALSA-2026:90523- Updated
- 2026-11-02
OSVAZL-105923 No score
CVE-2026-94422 affecting package xdg-dbus-proxy 0.1.6-2
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.
- Record
AZL-105923- Updated
- 2026-11-05
OSVMGASA-2026-0480 No score
Updated xdg-dbus-proxy package fixes a security vulnerability
Message filtering bypass via reply serial. (CVE-2026-94422)
- Record
MGASA-2026-0480- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11913-1 No score
xdg-dbus-proxy-0.1.9-1.1 on GA media
These are all security issues fixed in the xdg-dbus-proxy-0.1.9-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11913-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
xdg-dbus-proxyAlpine:v3.24 |
before 0.1.9-r0 | 0.1.9-r0 |
xdg-dbus-proxyAlmaLinux:9 |
before 0.1.3-1.el9_8.1 | 0.1.3-1.el9_8.1 |
xdg-dbus-proxyAlmaLinux:10 |
before 0.1.5-4.el10_2.1 | 0.1.5-4.el10_2.1 |
xdg-dbus-proxyAzure Linux:3 |
through 0.1.6-2 | None known |
xdg-dbus-proxyDebian:12 |
before 0.1.4-3+deb12u2, plus listed versions 0.1.4-30.1.4-3+deb12u1 |
0.1.4-3+deb12u2 |
xdg-dbus-proxyDebian:13 |
before 0.1.6-1+deb13u3, plus listed versions 0.1.6-10.1.6-1+deb13u10.1.6-1+deb13u2 |
0.1.6-1+deb13u3 |
xdg-dbus-proxyDebian:14 |
before 0.1.9-1, plus listed versions 0.1.6-10.1.6-20.1.7-10.1.8-1 |
0.1.9-1 |
xdg-dbus-proxyMageia:10 |
before 0.1.9-1.mga10 | 0.1.9-1.mga10 |
xdg-dbus-proxyopenEuler:22.03-LTS-SP4 |
before 0.1.2-3.oe2203sp4 | 0.1.2-3.oe2203sp4 |
xdg-dbus-proxyopenEuler:24.03-LTS-SP1 |
before 0.1.2-3.oe2403sp1 | 0.1.2-3.oe2403sp1 |
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| Package | Affected | Fixed |
|---|---|---|
xdg-dbus-proxyopenEuler:24.03-LTS-SP3 |
before 0.1.2-3.oe2403sp3 | 0.1.2-3.oe2403sp3 |
xdg-dbus-proxyopenEuler:24.03-LTS-SP4 |
before 0.1.2-3.oe2403sp4 | 0.1.2-3.oe2403sp4 |
xdg-dbus-proxyRocky Linux:9 |
before 0:0.1.3-1.el9_8.1 | 0:0.1.3-1.el9_8.1 |
xdg-dbus-proxyRocky Linux:10 |
before 0:0.1.5-4.el10_2.1 | 0:0.1.5-4.el10_2.1 |
xdg-dbus-proxyUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 0.1.1-10.1.2-10.1.2-1ubuntu0.1~esm1 |
None known |
xdg-dbus-proxyUbuntu:22.04:LTS |
All versions, plus listed versions 0.1.2-2build10.1.3-10.1.3-1ubuntu0.1 |
None known |
xdg-dbus-proxyUbuntu:24.04:LTS |
All versions, plus listed versions 0.1.5-10.1.5-1build10.1.5-1build20.1.5-1ubuntu0.10.1.5-1ubuntu0.2 |
None known |
xdg-dbus-proxyUbuntu:26.10 |
All versions, plus listed versions 0.1.7-10.1.8-10.1.9-1 |
None known |
xdg-dbus-proxyUbuntu:26.04:LTS |
All versions, plus listed versions 0.1.6-10.1.6-20.1.7-1 |
None known |
xdg-dbus-proxyopenSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 0.1.9-1.1 | 0.1.9-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| facts | OSV | |
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-94422 is a high vulnerability (CVSS 8.7) in Fedora, published September 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.50%, the 42nd percentile. Fixed in xdg-dbus-proxy 0.1.9-r0.
References
access.redhat.com/security/cve/CVE-2026-94422
github.com/flatpak/xdg-dbus-proxy/security/advisories/GHSA-2cgv-pwcq-wvpq
bugzilla.redhat.com/show_bug.cgi?id=2542235
Show 28 moreShow less
openwall.com/lists/oss-security/2026/09/23/5
lists.debian.org/debian-lts-announce/2026/10/msg00050.html
security.alpinelinux.org/vuln/CVE-2026-94422
errata.almalinux.org/9/ALSA-2026-90522.html
nvd.nist.gov/vuln/detail/CVE-2026-94422
bodhi.fedoraproject.org/updates?packages=xdg-dbus-proxy
security-tracker.debian.org/tracker/CVE-2026-94422
advisories.mageia.org/MGASA-2026-0480.html
bugs.mageia.org/show_bug.cgi?id=36369
lists.opensuse.org/archives/list/[email protected]/message/NKG63P7KLUREATNV6YUAI7RWYLCWSR6R
openeuler.org/zh/security/security-bulletins/detail?id=openEuler-SA-2026-4640
errata.rockylinux.org/RLSA-2026:90522
ubuntu.com/security/CVE-2026-94422
cve.org/CVERecord?id=CVE-2026-94422
suse.com/security/cve/CVE-2026-93676