CVE-2021-34647

The Ninja Forms WordPress plugin is vulnerable to sensitive information disclosure via the bulk_export_submissions function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to export all Ninja Forms submissions data via the /ninja-forms-submissions/export REST API which can include personally identifiable information.

Source: CVE-2021-34647