The WPeMatico RSS Feed Fetcher plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post_category' parameter in all versions up to, and including, 2.9.1 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 injected payload is persisted in post meta as campaign_data, bypassing wp_kses sanitization, and executes in the browser session of any user with edit_posts — including Administrators — who opens the WPeMatico campaigns list screen.