Vulnerability · Published Oct 23, 2026 · Assigned by GitHub_M
CVE-2026-55889XDG Desktop Portal: Drag-and-drop and copy-paste theft via predictable FileTransfer key
High 8.3
In plain English
A high-severity weak randomness in xdg-desktop-portal from flatpak. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | xdg-desktop-portal | no fix listed | DEBIAN-CVE-2026-55889 |
| Debian:13 | xdg-desktop-portal | no fix listed | DEBIAN-CVE-2026-55889 |
| Debian:14 | xdg-desktop-portal | 1.22.1+ds-1 | DEBIAN-CVE-2026-55889 |
| Ubuntu:22.04:LTS | xdg-desktop-portal | no fix listed | UBUNTU-CVE-2026-55889 |
| Ubuntu:24.04:LTS | xdg-desktop-portal | no fix listed | UBUNTU-CVE-2026-55889 |
| Ubuntu:26.04:LTS | xdg-desktop-portal | no fix listed | UBUNTU-CVE-2026-55889 |
| Ubuntu:26.10 | xdg-desktop-portal | no fix listed | UBUNTU-CVE-2026-55889 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| flatpak | xdg-desktop-portal | < 1.22.1 |
Weakness: CWE-330, CWE-337 · Vector: 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