This indicates an attack attempt to exploit a Cross Site Scripting vulnerability in WordPress WP e-Commerce Plug-in.
The vulnerability is a result of the application's failure to sanitize inputs from users. A remote attacker can execute arbitrary script code within the context of the application.
WordPress WP e-Commerce 3.8.6 and earlier versions.
System Compromise: Remote attackers can gain control of vulnerable systems.
Upgrade to the latest version available from the website.