The Schedule Post Changes With PublishPress Future plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wrapper' attribute of the [futureaction] shortcode in all versions up to, and including, 4.10.0. This is due to insufficient input sanitization on the wrapper attribute. The plugin uses esc_html() to escape the value, but esc_html() only encodes HTML entities and does not prevent attribute injection when the value is used as an HTML tag name in a sprintf() call. An attacker can inject event handler attributes via spaces in the wrapper value. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Since it is also possible for administrators to make this functionality available to lower-privileged users, this introduces the possibility of abuse by contributors.