{"id":"CVE-2026-30927","aliases":["EUVD-2026-10438","GHSA-7pfv-hr63-h7cw"],"status":"published","title":"Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter","description":"Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user-\u003egetValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00285,"percentile":0.21316,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-639"],"published":"2026-03-09T19:45:20Z","modified":"2026-10-28T02:30:28Z","fixes":[{"ecosystem":"Packagist","package":"admidio/admidio","fixed_in":["5.0.6"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"admidio/admidio","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.0.6"}]}]},{"source":"osv","ecosystem":"Packagist","package":"admidio/admidio","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.0.6"}]}],"versions":["4.1.0","4.1.3","v4.2-Beta.1","v4.2-Beta.2","v4.2-Beta.3","v4.2.0","v4.2.1","v4.2.10","v4.2.11","v4.2.12","v4.2.13","v4.2.14","v4.2.2","v4.2.3","v4.2.4","v4.2.5","v4.2.6","v4.2.7","v4.2.8","v4.2.9","v4.3-Beta.1","v4.3-Beta.3","v4.3-Beta.4","v4.3-Beta.5","v4.3.0","v4.3.1","v4.3.10","v4.3.11","v4.3.12","v4.3.13","v4.3.14","v4.3.15","v4.3.16","v4.3.17","v4.3.2","v4.3.3","v4.3.4","v4.3.5","v4.3.6","v4.3.7","v4.3.8","v4.3.9","v5.0-Beta.1","v5.0-Beta.2","v5.0-Beta.3","v5.0.0","v5.0.1","v5.0.2","v5.0.3","v5.0.4","v5.0.5"]}],"products":[{"vendor":"admidio","product":"admidio"}],"references":[{"url":"https://github.com/Admidio/admidio/security/advisories/GHSA-7pfv-hr63-h7cw","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/Admidio/admidio/issues/1985","tags":["x_refsource_MISC","Issue Tracking","report","web"]},{"url":"https://github.com/Admidio/admidio/commit/e47f70cc3cbcdb39635fdbaaef02d19f604b8c3e","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-30927","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7pfv-hr63-h7cw"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30927.json","tags":["advisory"]},{"url":"https://github.com/Admidio/admidio","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-30927","title":"Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter","description":"Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user-\u003egetValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.","status":"published","published":"2026-03-09T23:03:55.824Z","modified":"2026-03-10T13:59:12.645Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T13:44:07.200604Z"}],"euvd":[{"id":"EUVD-2026-10438","description":"Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user-\u003egetValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.","status":"published","published":"2026-03-09T23:03:55Z","modified":"2026-03-10T13:59:12Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:48:05.412027Z"}],"ghsa":[{"id":"GHSA-7pfv-hr63-h7cw","title":"Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter","description":"## Vulnerability\n\nIn `modules/events/events_function.php`, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the `user_uuid` GET parameter.\n\nLine 47: `$getUserUuid = admFuncVariableIsValid($_GET, 'user_uuid', 'uuid', ...)`\nLine 424: `if ($event-\u003epossibleToParticipate() || $participants-\u003eisLeader($gCurrentUserId))`\n\nThe condition uses `||` (OR), meaning if `possibleToParticipate()` returns true (event is open for participation), ANY user - not just leaders - can specify a different `user_uuid` and register/cancel participation for that user.\n\nThe code then operates on `$user-\u003egetValue('usr_id')` (the target user from user_uuid) rather than the current user.\n\n## Impact\n- Register unwilling users for events (potential harassment/spam)\n- Cancel other users' event participation\n- Manipulate event participant counts and comments\n- If events have participation limits, fill slots with unwanted registrations\n\n## Fix\nFor non-leader users, force `user_uuid` to the current user:\n```php\nif (!$participants-\u003eisLeader($gCurrentUserId)) {\n    $getUserUuid = $gCurrentUser-\u003egetValue('usr_uuid');\n}\n```","status":"published","published":"2026-03-09T19:45:20Z","modified":"2026-03-10T18:39:34Z","cvss":[{"version":"3.1","score":0,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N","level":"none"},{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T14:39:33.538417Z"}],"nvd":[{"id":"CVE-2026-30927","description":"Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user-\u003egetValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.","status":"published","published":"2026-03-10T17:40:16.52Z","modified":"2026-06-17T10:33:09.9Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/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","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"primary"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T14:12:08.279852Z"}],"osv":[{"id":"CVE-2026-30927","title":"Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter","description":"Admidio is an open-source user management solution. Prior to 5.0.6, in modules/events/events_function.php, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the user_uuid GET parameter. The condition uses || (OR), meaning if possibleToParticipate() returns true (event is open for participation), ANY user - not just leaders - can specify a different user_uuid and register/cancel participation for that user. The code then operates on $user-\u003egetValue('usr_id') (the target user from user_uuid) rather than the current user. This vulnerability is fixed in 5.0.6.","status":"published","published":"2026-03-09T23:03:55.824Z","modified":"2026-10-28T02:30:28.932817108Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T15:45:00.861953Z"},{"id":"GHSA-7pfv-hr63-h7cw","title":"Admidio: Event participation IDOR - non-leaders can register other users for events via user_uuid parameter","description":"## Vulnerability\n\nIn `modules/events/events_function.php`, the event participation logic allows any user who can participate in an event to register OTHER users by manipulating the `user_uuid` GET parameter.\n\nLine 47: `$getUserUuid = admFuncVariableIsValid($_GET, 'user_uuid', 'uuid', ...)`\nLine 424: `if ($event-\u003epossibleToParticipate() || $participants-\u003eisLeader($gCurrentUserId))`\n\nThe condition uses `||` (OR), meaning if `possibleToParticipate()` returns true (event is open for participation), ANY user - not just leaders - can specify a different `user_uuid` and register/cancel participation for that user.\n\nThe code then operates on `$user-\u003egetValue('usr_id')` (the target user from user_uuid) rather than the current user.\n\n## Impact\n- Register unwilling users for events (potential harassment/spam)\n- Cancel other users' event participation\n- Manipulate event participant counts and comments\n- If events have participation limits, fill slots with unwanted registrations\n\n## Fix\nFor non-leader users, force `user_uuid` to the current user:\n```php\nif (!$participants-\u003eisLeader($gCurrentUserId)) {\n    $getUserUuid = $gCurrentUser-\u003egetValue('usr_uuid');\n}\n```","status":"published","published":"2026-03-09T19:45:20Z","modified":"2026-03-10T18:48:30.504905Z","cvss":[{"version":"3.1","score":0,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N","level":"none"},{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-639"],"updated_at":"2026-11-02T15:46:41.349637Z"}]}}