The RSS Aggregator by Feedzy – Feed to Post, Autoblogging, News & YouTube Video Feeds Aggregator plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'media:thumbnail@url' parameter in all versions up to, and including, 5.2.11 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 requires the attacker to control an external RSS feed that the target site has already configured for import; no WordPress account or special plugin configuration is needed beyond that condition.