# CVE-2026-55888: XDG Desktop Portal: Arbitrary file access via SaveFiles "files" option path traversal


- **Severity:** High 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`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-55888, GHSA-cm83-2936-gxjm, OESA-2026-2998, OESA-2026-2999, OESA-2026-3000, UBUNTU-CVE-2026-55888

## What is CVE-2026-55888?

CVE-2026-55888 is a high-severity vulnerability in flatpak xdg-desktop-portal, published on 23 Oct 2026. 

### Official 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.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-55888?


## How do I fix CVE-2026-55888?

Upgrade to a fixed version.

## Is CVE-2026-55888 being exploited?

There is no known exploitation of CVE-2026-55888 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55888 and fix it if it is affected.

What it is: CVE-2026-55888 is a high-severity vulnerability in flatpak xdg-desktop-portal, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-55888 in the wild and no public exploit code.

Affected product: flatpak xdg-desktop-portal. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55888/ (Markdown: https://insights.sbomify.com/CVE-2026-55888/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55888
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55888
- OSV: https://osv.dev/vulnerability/CVE-2026-55888

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55888/
Summaries are generated and may contain mistakes; the official description above is the record.