CVE-2026-41659: Admidio Leaks Hidden Profile Field Values via Blind Search Oracle in Member Assignment

The member assignment DataTables endpoint (members_assignment_data.php) includes hidden profile fields (BIRTHDAY, STREET, CITY, POSTCODE, COUNTRY) in its SQL search condition regardless of field visibility settings. While the JSON output correctly suppresses hidden columns via isVisible() checks, the server-side search operates at the SQL level before any visibility filtering. This allows a role leader with assign-only permissions to infer hidden PII values by observing which users appear in search results for specific values.