The Ninja Forms WordPress plugin from 3.14.10 before 3.15.2 does not prevent shortcodes in request-derived values from being executed when it substitutes them into content it later processes for shortcodes, allowing unauthenticated users to run any shortcode registered on the site.
https://wpscan.com/vulnerability/473a3321-7dc6-454a-82f4-89b6a393d09a/