The Mang Board plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'content' parameter in all versions up to, and including, 2.4.3 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. This is exploitable because the wp_ajax_nopriv_mb_template endpoint is publicly accessible without authentication, nonce verification is not enforced for the content_reply mode, and admin-ajax.php responds with Content-Type: text/html, causing browsers to execute injected tags embedded in the JSON response body.