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Fencer Vulns
high 8.8

CVE-2026-55888 json

XDG Desktop Portal: Arbitrary file access via SaveFiles "files" option path traversal

published 2026-10-23 17 d ago modified 2026-10-30 10 d ago also EUVD-2026-108752

cvss
8.8
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

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.

Patch / fix

  • flatpak xdg-desktop-portal 1.22.1
  • xdg-desktop-portal Debian 14 1.22.1+ds-1

debian advisories DEBIAN-CVE-2026-55888

  • xdg-desktop-portal SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 1.16.0-150500.3.13.1

suse advisories SUSE-SU-2026:5098-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-55888 updated cvss 8.2

xdg-desktop-portal: xdg-desktop-portal: Unauthorized host file access via unvalidated FileChooser filenames

  • Red Hat Enterprise Linux 7 xdg-desktop-portal, xdg-desktop-portal 1.20.0-2.el10 Red Hat Enterprise Linux 8 xdg-desktop-portal, xdg-desktop-portal 1.20.0-2.el10 Red Hat Enterprise Linux 9 xdg-desktop-portal 1.20.0-2.el10 Red Hat Enterprise Linux 10 xdg-desktop-portal 1.20.0-2.el10
    affected: workaround, no fix available

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 d ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/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

Affected products

  • flatpak xdg-desktop-portal

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.