Ninja Forms Cross-Site Network-Wide Data Deletion on WordPress Multisite via nf_delete_all_data AJAX Action

Ninja Forms plugin version 3.14.8 and prior for WordPress Multisite contains an incorrect authorization vulnerability that allows a subsite Administrator to trigger network-wide deletion of all Ninja Forms data by exploiting a site-scoped capability check combined with unsafe multisite migration defaults. Attackers can send a crafted POST request to the admin-ajax.php endpoint with the nf_delete_all_data action and a per-site nonce to invoke migration routines that unconditionally iterate all blogs via switch_to_blog(), dropping all nf3_* tables and clearing options and transients across every subsite in the network without requiring super-admin or network-admin privileges.