{"id":"CVE-2026-55889","kind":"vulnerability","aliases":["CVE-2026-55889"],"related":[],"title":"XDG Desktop Portal: sandboxed apps can hijack clipboard and drag-and-drop data","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.","summary":"XDG Desktop Portal before 1.22.1 lets a malicious sandboxed app call FileTransfer.RetrieveFiles to redirect drag-and-drop and copy-paste data meant for other apps. Its access tokens come from GLib's Mersenne Twister PRNG, so an attacker who collects enough tokens can predict later ones.","severity":"high","cvss":8.3,"epss":0.00365,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["desktop","flatpak","infrastructure","linux","xdg-desktop-portal"],"not_affected_if":["no-sandboxed-apps","no-xdg-desktop-portal"],"how_to_check":"- Run `xdg-desktop-portal --version` and compare it with `1.22.1`.\n- Check the installed package version with your distro's package manager (for example `rpm -q xdg-desktop-portal` or `dpkg -s xdg-desktop-portal`).","fix":"- Upgrade xdg-desktop-portal to `1.22.1` or later.","status":"open","published_at":"2026-10-23T13:17:10+00:00","first_seen_at":"2026-10-23T21:57:33+00:00","triaged_at":"2026-10-25T03:02:03+00:00","updated_at":"2026-10-25T12:38:50+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-25T03:02:03Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade xdg-desktop-portal to `1.22.1` or later.","reach":"local","title":"XDG Desktop Portal: sandboxed apps can hijack clipboard and drag-and-drop data","impact":"medium","summary":"XDG Desktop Portal before 1.22.1 lets a malicious sandboxed app call FileTransfer.RetrieveFiles to redirect drag-and-drop and copy-paste data meant for other apps. Its access tokens come from GLib's Mersenne Twister PRNG, so an attacker who collects enough tokens can predict later ones.","category":"infrastructure","nicknames":[],"who_cares":["linux","flatpak","desktop","xdg-desktop-portal"],"confidence":0.6,"needs_auth":"unknown","worst_case":"sandboxed app takes other apps' clipboard and drop data, predicts tokens","analyst_note":"Confirm the affected package versions and whether unsandboxed apps are reachable, using the NVD entry and the upstream xdg-desktop-portal 1.22.1 release notes.","how_to_check":"- Run `xdg-desktop-portal --version` and compare it with `1.22.1`.\n- Check the installed package version with your distro's package manager (for example `rpm -q xdg-desktop-portal` or `dpkg -s xdg-desktop-portal`).","needs_analyst":true,"not_affected_if":["no-sandboxed-apps","no-xdg-desktop-portal"],"who_is_affected":"Linux desktops and workstations that run xdg-desktop-portal and host sandboxed applications (Flatpak or Snap apps) alongside other apps that exchange clipboard or drag-and-drop data. Systems without xdg-desktop-portal, or with no sandboxed apps, are less exposed. The sources do not say whether non-sandboxed apps are at risk.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000688,"input_tokens":3452,"output_tokens":685,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':16A,19A '-55889':17A,20A '1.22.1':33B,88C,203C 'access':57B,120C,129C 'app':5A,38B,55B 'applic':91C,111C 'attack':68B 'band':140C 'base':161C 'call':39B 'clipboard':8A 'collect':70B 'come':59B 'copi':49B,105C 'copy-past':48B,104C 'creat':168C 'cve':15A,18A 'data':14A,51B,107C 'desktop':2A,21B,27B,30B,78C,82C 'drag':11A,44B,100C 'drag-and-drop':10A,43B,99C 'drop':13A,46B,102C 'enough':71B,177C 'filetransfer.retrievefiles':40B,95C 'flatpak':22B 'g':146C,150C 'generat':116C,144C,176C 'glib':61B,158C 'grand':160C,183C 'happen':137C 'hijack':7A 'infrastructur':23B 'int':148C 'integr':83C 'issu':197C 'later':75B 'let':34B 'linux':24B 'malici':36B,89C 'meant':52B 'mersenn':63B,164C 'method':96C 'next':191C 'number':174C 'one':76B 'past':50B,106C 'patch':200C 'portal':3A,28B,31B,79C,84C,115C 'predict':74B 'predictedinsufin':195C 'prior':85C 'prng':65B,166C 'provid':119C 'random':147C,153C,173C 'recov':186C 'redirect':42B,98C 'reproduc':172C 'resourc':122C,132C 'sandbox':4A,37B,90C 'share':124C 'state':180C 'stream':170C 'string':152C 'suppos':135C 'target':108C 'token':58B,72B,117C,127C,142C,178C,192C 'transfer':128C 'twister':64B,165C 'use':93C,157C 'uuid':151C 'version':87C,202C 'xdg':1A,26B,29B,77C 'xdg-desktop-port':25B","nicknames":[],"mitigations":[],"who_affected":"Linux desktops and workstations that run xdg-desktop-portal and host sandboxed applications (Flatpak or Snap apps) alongside other apps that exchange clipboard or drag-and-drop data. Systems without xdg-desktop-portal, or with no sandboxed apps, are less exposed. The sources do not say whether non-sandboxed apps are at risk.","tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-23T13:17:10+00:00","kev":null,"cvss_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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-55889","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55889","severity":null,"published_at":"2026-10-23T13:17:10+00:00","modified_at":"2026-10-23T19:42:24+00:00","first_seen_at":"2026-10-23T21:57:33+00:00","fetched_at":"2026-10-23T22:29:03+00:00","note":null},{"source":"epss","external_id":"CVE-2026-55889","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-55889","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-25T12:38:50+00:00","fetched_at":"2026-10-25T12:38:50+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}