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TI-2026-65935 Aliases CVE-2026-94422

xdg-dbus-proxy: message filtering bypass via reply serial allows sandbox escape

Priority MEDIUM 40CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-290.

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 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00497 42nd percentileScored 2026-11-07
Fix Fixed xdg-dbus-proxy: 0.1.9Fedora (Fedora): 0.1.9Red Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
—xdg-dbus-proxybefore 0.1.90.1.9Patch availableCNA
FedoraFedorabefore 0.1.90.1.9Patch availableCNA
Red HatRed Hat Enterprise Linux 9——No fix listedCNA
Red HatRed Hat Enterprise Linux 10——No fix listedCNA
  • xdg-dbus-proxy Vendor— Affected before 0.1.9 Fixed in 0.1.9 Patch available CNA
  • Fedora VendorFedora Affected before 0.1.9 Fixed in 0.1.9 Patch available CNA
  • Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 2

CPEVersionsRoleVendor
cpe:/o:redhat:enterprise_linux:99—Red Hat
cpe:/o:redhat:enterprise_linux:1010—Red Hat
  • cpe:/o:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
  • cpe:/o:redhat:enterprise_linux:10 Versions 10 — ·Red Hat

Remediation

  • Fix · CNA xdg-dbus-proxy Fixed in 0.1.9
  • Fix · CNA Fedora (Fedora) Fixed in 0.1.9

Red Hat 4 advisories

  • RHSA-2026:91625 Released 2026-10-28 · Red Hat rating Important
    xdg-dbus-proxy security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) xdg-dbus-proxy-0.1.3-1.el9_6.1
  • RHSA-2026:91623 Released 2026-10-28 · Red Hat rating Important
    xdg-dbus-proxy security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) xdg-dbus-proxy-0.1.3-1.el9_4.1
  • RHSA-2026:90522 Released 2026-10-27 · Red Hat rating Important
    xdg-dbus-proxy security update
    • Red Hat Enterprise Linux AppStream (v. 9) xdg-dbus-proxy-0.1.3-1.el9_8.1
Show 1 more Red Hat advisories
  • RHSA-2026:90523 Released 2026-10-27 · Red Hat rating Important
    xdg-dbus-proxy security update
    • Red Hat Enterprise Linux AppStream (v. 10) xdg-dbus-proxy-0.1.5-4.el10_2.1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:90523
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:90522
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:91624
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:91623
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:91626
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:91625

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-94422
  2. 2026-10-04 Priority changed: LOW → MEDIUM
  3. 2026-10-25 EPSS moved to the below the 50th percentile
  4. 2026-10-27 Fix available: Red Hat Enterprise Linux AppStream (v. 10) · Red Hat
  5. 2026-10-27 Fix available: Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
  6. 2026-10-29 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.6) · Red Hat
  7. 2026-10-29 Fix available: RHSA-2026:90523 · Red Hat
  8. 2026-10-29 Fix available: RHSA-2026:90522 · Red Hat
  9. 2026-10-29 Fix available: RHSA-2026:91623 · Red Hat
  10. 2026-10-29 Fix available: RHSA-2026:91625 · Red Hat
  11. 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux AppStream EUS (v. 10.0) · Red Hat

References

Patch 3

Advisory 2

Other 1

  • TI-2018-01029 Command injection in Red Hat dhcp CVSS 3.0HIGH 7.5
  • TI-2024-01796 Improper input validation in Fedora dnf5daemon-server CVSS 3.1HIGH 8.4
  • TI-2023-05737 Glibc: heap-based buffer overflow in __vsyslog_internal() CVSS 3.1HIGH 8.4
  • TI-2023-03845 Heap out of bound read in builtin.c CVSS 3.1HIGH 7.1
  • TI-2023-04922 Draw while calling getdrawinfo() CVSS 3.1MEDIUM 5.3
  • TI-2023-03123 Crash due to a null pointer dereference in the dn_nsp_send function CVSS 3.1MEDIUM 6.5
See all 95 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences