The NEX-Forms – Ultimate Form Builder – Contact forms and much more plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the clean_html and form_fields parameters in all versions up to, and including, 8.9.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Custom-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
CWE-79