WPForms Lite <= 1.9.5 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'start_timestamp' Parameter

The WPForms – Easy Form Builder for WordPress – Contact Forms, Payment Forms, Surveys, & More plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the start_timestamp parameter in all versions up to, and including, 1.9.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.