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TI-2026-79756 Aliases CVE-2026-55888

Path traversal in XDG Desktop Portal allows arbitrary file access

Priority MEDIUM 44CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
Low · High · None
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

XDG Desktop Portal before 1.22.1 is affected. The FileChooser.SaveFiles method does not validate the optional filenames it appends to the selected directory, so path traversal (CWE-22) is possible. A malicious sandboxed application can use this without user interaction to gain access to non-existing files on the host that the user can access.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

XDG Desktop Portal is a desktop integration portal. Prior to version 1.22.1, malicious sandboxed applications can use the FileChooser.SaveFiles method to gain arbitrary file access to non-existing files on the host (limited to files the user has access to). The FileChooser.SaveFiles method takes optional filenames which get appended to the selected directory by backends. The backends are supposed to check that the file does not exist yet. The filenames are not validated by the frontend and also not by common backends. This issue has been patched in version 1.22.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00454 39th percentileScored 2026-11-07
Fix Partial xdg-desktop-portal (flatpak): 1.22.1Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
flatpakxdg-desktop-portalbefore 1.22.11.22.1Patch availableCNA
  • xdg-desktop-portal Vendorflatpak Affected before 1.22.1 Fixed in 1.22.1 Patch available CNA

Remediation

Update xdg-desktop-portal to version 1.22.1 or later. Red Hat lists no available fix for Red Hat Enterprise Linux 10, 7, 8 and 9.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA xdg-desktop-portal (flatpak) Fixed in 1.22.1

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-55888
  2. 2026-10-24 Priority changed: MEDIUM → LOW
  3. 2026-10-24 Affected versions changed · Red Hat
  4. 2026-10-24 CVSS score added · Red Hat
  5. 2026-10-30 CISA SSVC decision points changed
  6. 2026-10-30 Priority changed: LOW → MEDIUM

References

Other 2

  • TI-2026-28833 flatpak-builder has a path traversal leading to arbitrary file read on host when installing licence files CVSS 4.0HIGH 7.1
  • TI-2026-26401 Flatpak has a complete sandbox escape leading to host file access and code execution in the host context CVSS 4.0CRITICAL 9.3
  • TI-2024-28440 Flatpak may allow access to files outside sandbox for certain apps CVSS 3.1CRITICAL 10.0
  • TI-2023-12679 TIOCLINUX can send commands outside sandbox if running on a virtual console CVSS 3.1CRITICAL 10.0
  • TI-2026-26402 Flatpak affected by arbitrary file deletion on the host filesystem CVSS 4.0HIGH 8.7
  • TI-2019-07389 Flatpak before 1.0.8, 1.1.x and 1.2.x before 1.2.4, and 1.3.x before 1.3.1 allows a… CVSS 3.0CRITICAL 9.0
See all 23 →

Sources

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