The Document Embedder – let visitors read files without downloading plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'content (post_content containing block JSON documentSource.doc)' parameter in all versions up to, and including, 2.4.0 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. The payload is triggered specifically when the victim clicks the embedded document's Download button, which causes the de_track_download AJAX fallback path to programmatically create an anchor with the attacker-controlled href and call .click() — a condition reached because supplying docId=0 causes can_read_document() to return false, bypassing the normal download flow.