CVE-2026-47231: Admidio has IDOR in `documents-files.php` `mode=move_save` that lets any folder-uploader exfiltrate files from private folders

modules/documents-files.php gates state-changing modes by checking that the actor has hasUploadRight() on the URL parameter folder_uuid. The move_save handler then operates on a separate URL parameter file_uuid and calls File::moveToFolder($destFolderUUID). File::moveToFolder() checks the upload right on the destination folder but never on the source folder containing the file. As a result, any user who can upload to any single folder can move any file from any other folder — including private folders to which they have no view rights — into a folder they control, and then download it. Confidentiality is broken (private file contents leak) and integrity is broken (the file is removed from the original location).