See how metabox compares to other vendors in security performance
The Meta Box plugin before 4.16.2 for WordPress mishandles the uploading of files to custom folders.
The Meta Box plugin before 4.16.3 for WordPress allows file deletion via ajax, with the wp-admin/admin-ajax.php?action=rwmbdeletefile attachmentid parameter.
The Meta Box – WordPress Custom Fields Framework plugin for WordPress is vulnerable to Stored Cross-Site Scripting via custom post meta values displayed through the plugin's shortcode in all versions up to, and including, 5.9.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
The Meta Box WordPress plugin before 5.9.4 does not prevent users with at least the contributor role from access arbitrary custom fields assigned to other user's posts.