Forminator Forms <= 1.56.1 - Unauthenticated Stored Cross-Site Scripting via Forged Upload Record via Select Field

The Forminator Forms – Contact Form, Payment Form & Custom Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Forged Upload Record via Select Field in all versions up to, and including, 1.56.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit is possible because Forminator_Core::sanitize_array() skips all filtering for keys prefixed with 'select-', and set_field_data() treats a submitted 'return' member as a trusted internal flag — allowing an unauthenticated attacker to forge and persist a complete upload field record with an arbitrary file_url value without any sanitization or validation.