CVE-2026-55889 XDG Desktop Portal: Drag-and-drop and copy-paste theft via predictable FileTransfer key
- Exploited in the wild
- Not known
- Fix
- Available
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.
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.
Sources
Also known as DEBIAN-CVE-2026-55889, GHSA-c5cf-79w8-pvfh, UBUNTU-CVE-2026-55889.