The Zypento Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Table of Contents block in all versions up to, and including, 1.0.6. This is due to the front-end TOC rendering script reading heading text via `innerText` and inserting it into the page using `innerHTML` without proper sanitization. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.