XDG Desktop Portal: Arbitrary file access via SaveFiles "files" option path traversal
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Fix
- Fixed in 1.22.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
XDG Desktop Portal, a desktop integration component used on Linux systems, is affected. A malicious sandboxed application can abuse its file-saving feature to create or write to files outside its permitted area on the host, limited to locations the user can already access.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
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.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- flatpak xdg-desktop-portal
fixed in 1.22.1
References 2
GitHub · flatpak/xdg-desktop-portal
Questions about CVE-2026-55888
What does this mean?
A sandboxed application can use the FileChooser.SaveFiles method with the "files" option to write to paths outside what it should reach. That gives it arbitrary access to non-existing files on the host, limited to files the user can already access.Source: github.com
Am I affected, and how do I check?
Versions up to and including 1.22.0 of xdg-desktop-portal are affected. To check a system, run xdg-desktop-portal --version and compare the number with 1.22.1, the first fixed release.Source: github.com
What should I do about it?
Upgrade xdg-desktop-portal to 1.22.1 or later, which contains the patch for this issue.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data