The MP3 Audio Player – Music Player, Podcast Player & Radio by Sonaar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 5.14.2 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. WordPress's save-time wp_kses_post does not neutralize the payload because the attack is delivered via shortcode attributes rather than raw HTML in post content, allowing the unescaped values to survive to render time.