The Mutual Funds Data plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute in versions up to, and including, 1.2.1. This is due to insufficient input sanitization and output escaping on the user supplied 'title' attribute in the mfd_shortcode() function, which is concatenated directly into the HTML output within a <caption> element. 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.