The Download Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'no_data_msg' Shortcode Attribute in all versions up to, and including, 3.3.60 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. Although wp_kses_post is applied to post content on save, it only strips HTML tokens and does not neutralize C-style escape sequences embedded within shortcode attribute values, meaning contributors can craft a payload that survives the kses filter and is silently reconstructed into a raw script tag at render time.