CVE-2026-82657

Admidio before 5.0.17 contains an improper access control vulnerability that allows authenticated members to register event guests by submitting the additional_guests field when guests are disallowed. An attacker can set additional_guests to the remaining seat count in modules/events/events_function.php to exhaust event capacity and block other members from registering.

Admidio is an open-source user management solution. Prior to version 5.0.9, a logic error in Admidio's two-factor authentication reset inverts the authorization check, allowing non-admin users to remove other users' TOTP configurations, including administrators.

Admidio before 5.0.16 contains an information disclosure vulnerability that allows unauthenticated attackers to view role-restricted weblinks because rss/links.php omits the category_view role-visibility filter. Attackers can request the weblinks RSS feed for an organization to retrieve link names, URLs, descriptions, categories, and creator names from restricted LNK categories.

Admidio from 5.0.11 before 5.0.16 contains a broken access control vulnerability in modules/inventory/inventory_data.php that allows authenticated users to bypass the inventory_module_enabled restriction. Attackers with any valid login can request the DataTables JSON feed to read every inventory item and keeper names, even when the module is disabled.

Admidio from 5.0.0 before 5.0.16 contains an authorization bypass vulnerability that allows authenticated users to export lists despite export restrictions by requesting mode=pdfl. The groups_roles_export check in modules/groups-roles/lists_show.php omits pdfl, which later runs the pdf export, letting users with list view rights download member lists as PDF files.

Admidio from 5.0.0 before 5.0.16 contains an insecure direct object reference vulnerability in ForumService::saveTopic() that allows authenticated members to modify other users' forum topics. Attackers can replace the topic_uuid parameter in their own topic_save request, reusing their CSRF token, to overwrite the victim topic's title and first post.

Admidio 4.3.2 through 4.3.17 and 5.0.0 before 5.0.15 contains a broken access control vulnerability that allows role administrators to assign users to roles in other organizations. Attackers can submit crafted assign requests to members_assignment.php with a foreign role UUID to gain privileged membership, log into that organization, and edit its user profiles.

Admidio 5.0.0 before 5.0.15 contains an unauthenticated stored cross-site scripting vulnerability in RegistrationPresenter.php, which inserts the raw FIRST_NAME registration value into an unencoded data-message attribute. Attackers can register with a double-quoted event handler that executes JavaScript in an administrator's session when they hover the entry on the Manage registrations page.

Admidio 4.0.12 through 4.3.17 and 5.0.0 before 5.0.15 contains a reflected cross-site scripting vulnerability in system/redirect.php that allows unauthenticated attackers to inject JavaScript via the url GET parameter, due to an incomplete fix for CVE-2021-43810. Attackers can craft a javascript: URL containing a decoy http:// segment that passes validation and executes script in the Admidio origin when victims click the redirect link.

Admidio up to version 5.0.11 has a CSRF vulnerability in modules/plugins.php, where plugin installation, uninstallation, and update operations are performed via GET requests without CSRF token validation. An attacker can craft a malicious page that, when visited by an authenticated administrator, triggers arbitrary plugin operations, including uninstallation, which executes DROP TABLE SQL scripts and destroys plugin data.