PowerPress Podcasting plugin by Blubrry <= 11.18.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'width' and 'height' Shortcode Attributes

The PowerPress Podcasting plugin by Blubrry plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'width' parameter in all versions up to, and including, 11.18.0 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. This vulnerability is only exploitable when the site's configured video player is set to html5video, or when the media URL uses a .webm or .ogv extension, as these conditions are required to route the shortcode attributes through the vulnerable powerpressplayer_build_html5video() builder. Successful exploitation additionally requires an action by an editor — the attacker cannot trigger the vulnerability on their own.