Bug 2559821 (CVE-2026-55889)

Summary: CVE-2026-55889 xdg-desktop-portal: xdg-desktop-portal: unauthorized data disclosure via predictable token generation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in xdg-desktop-portal. The service uses a predictable pseudorandom number generator (PRNG) to generate authorization tokens that manage access to shared system resources. By requesting enough tokens to determine the internal state of the generator, a malicious sandboxed application can predict future tokens. This flaw allows an attacker to intercept or redirect clipboard and drag-and-drop data intended for other applications, resulting in unauthorized data disclosure.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2565123    
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Description OSIDB Bzimport 2026-10-23 13:47:06 UTC 
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.