CVE-2026-55889
Received
Received - Intake
XDG Desktop Portal Token Predictability via PRNG
Vulnerability report for CVE-2026-55889, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: GitHub, Inc.
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| flatpak | xdg-desktop-portal | < 1.22.1 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-330 | The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. |
| CWE-337 | A Pseudo-Random Number Generator (PRNG) is initialized from a predictable seed, such as the process ID or system time. |
