{"id":"CVE-2026-50539","kind":"vulnerability","aliases":["CVE-2026-50539"],"related":[],"title":"Xibo: any logged-in user can download admin notification attachments","description":"Xibo is an open source digital signage platform with a web content management system and Windows display player software. Prior to 4.4.3, missing object-level authorization on `/notification/export/{id}` allows an authenticated user to download attachments from any notification, including notifications created by administrators, by iterating over `sequential notification IDs`. Exploitation requires access to the `Notification Centre` to view past notifications, a privilege granted to non-administrators as standard. This issue is fixed in version 4.4.3.","summary":"Xibo digital signage platform before 4.4.3 lacks an object-level authorization check on the notification export endpoint. An authenticated non-admin user can iterate sequential notification IDs and download attachments from any notification, including ones created by administrators.","severity":"medium","cvss":6.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["digital-signage","package","self-hosted","xibo"],"not_affected_if":["no-non-admin-users","version-4.4.3-or-later"],"how_to_check":"- Check the Xibo CMS version in the admin UI or package files; versions below `4.4.3` are affected.\n- Confirm whether non-admin users have access to the Notification Centre, which is granted by default.","fix":"- Upgrade Xibo CMS to `4.4.3` or later.\n- Until upgraded, review notification attachments for sensitive content and limit non-admin access to the Notification Centre.","status":"open","published_at":"2026-10-28T16:17:07+00:00","first_seen_at":"2026-10-28T16:33:49+00:00","triaged_at":"2026-10-28T16:35:54+00:00","updated_at":"2026-10-28T16:35:54+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-28T16:35:54Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Xibo CMS to `4.4.3` or later.\n- Until upgraded, review notification attachments for sensitive content and limit non-admin access to the Notification Centre.","reach":"network","title":"Xibo: any logged-in user can download admin notification attachments","impact":"medium","summary":"Xibo digital signage platform before 4.4.3 lacks an object-level authorization check on the notification export endpoint. An authenticated non-admin user can iterate sequential notification IDs and download attachments from any notification, including ones created by administrators.","category":"package","nicknames":[],"who_cares":["xibo","self-hosted","digital-signage"],"confidence":0.8,"needs_auth":"yes","worst_case":"Authenticated users read attachments from administrator notifications","analyst_note":"","how_to_check":"- Check the Xibo CMS version in the admin UI or package files; versions below `4.4.3` are affected.\n- Confirm whether non-admin users have access to the Notification Centre, which is granted by default.","needs_analyst":false,"not_affected_if":["version-4.4.3-or-later","no-non-admin-users"],"who_is_affected":"Self-hosted or managed Xibo CMS instances running versions before 4.4.3 that have non-administrator user accounts with access to the Notification Centre. Exposure requires an authenticated account, so instances without user accounts beyond administrators are less exposed. unknown whether managed hosting by the vendor has already been patched.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.00061,"input_tokens":3367,"output_tokens":546,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-50539':14A,17A '/notification/export':94C '4.4.3':31B,87C,143C 'access':119C 'admin':9A,48B 'administr':65B,110C,134C 'allow':96C 'attach':11A,57B,102C 'authent':45B,98C 'author':37B,92C 'centr':123C 'check':38B 'content':77C 'creat':63B,108C 'cve':12A,15A 'digit':19B,27B,71C 'digital-signag':18B 'display':82C 'download':8A,56B,101C 'endpoint':43B 'exploit':117C 'export':42B 'fix':140C 'grant':130C 'host':24B 'id':54B,95C,116C 'includ':61B,106C 'issu':138C 'iter':51B,112C 'lack':32B 'level':36B,91C 'log':4A 'logged-in':3A 'manag':78C 'miss':88C 'non':47B,133C 'non-admin':46B 'non-administr':132C 'notif':10A,41B,53B,60B,105C,107C,115C,122C,127C 'object':35B,90C 'object-level':34B,89C 'one':62B 'open':69C 'packag':21B 'past':126C 'platform':29B,73C 'player':83C 'prior':85C 'privileg':129C 'requir':118C 'self':23B 'self-host':22B 'sequenti':52B,114C 'signag':20B,28B,72C 'softwar':84C 'sourc':70C 'standard':136C 'system':79C 'user':6A,49B,99C 'version':142C 'view':125C 'web':76C 'window':81C 'xibo':1A,25B,26B,66C","nicknames":[],"mitigations":[],"who_affected":"Self-hosted or managed Xibo CMS instances running versions before 4.4.3 that have non-administrator user accounts with access to the Notification Centre. Exposure requires an authenticated account, so instances without user accounts beyond administrators are less exposed. unknown whether managed hosting by the vendor has already been patched.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T16:17:07+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-50539","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50539","severity":null,"published_at":"2026-10-28T16:17:07+00:00","modified_at":"2026-10-28T16:17:07+00:00","first_seen_at":"2026-10-28T16:33:49+00:00","fetched_at":"2026-10-28T16:33:49+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"}