# CVE-2026-55889: XDG Desktop Portal: Drag-and-drop and copy-paste theft via predictable FileTransfer key


- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/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-2026-55889, GHSA-c5cf-79w8-pvfh, UBUNTU-CVE-2026-55889

## What is CVE-2026-55889?

CVE-2026-55889 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 FileTransfer.RetrieveFiles method to redirect drag-and-drop and copy-paste data targeted at other applications to itself. Some portals generate tokens which provide access to resources. The sharing of the token transfers access to the resource and is supposed to happen out of band. The tokens were generated with g_random_int or g_uuid_string_random, both of which use GLib's GRand based on the Mersenne Twister PRNG which created a stream of reproducible random numbers. By generating enough tokens, the state of the GRand can be recover and with it, the next tokens can be predictedinsufin. This issue has been patched in version 1.22.1.

Weakness: CWE-337 (Predictable Seed in Pseudo-Random Number Generator (PRNG)), CWE-330 (Use of Insufficiently Random Values)

## Which versions are affected by CVE-2026-55889?


## How do I fix CVE-2026-55889?

Upgrade to a fixed version.

## Is CVE-2026-55889 being exploited?

There is no known exploitation of CVE-2026-55889 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55889 and fix it if it is affected.

What it is: CVE-2026-55889 is a high-severity vulnerability in flatpak xdg-desktop-portal, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-55889 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-2026-55889/ (Markdown: https://insights.sbomify.com/CVE-2026-55889/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55889
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55889
- OSV: https://osv.dev/vulnerability/CVE-2026-55889

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55889/
Summaries are generated and may contain mistakes; the official description above is the record.