The July cumulative security update for Internet Explorer 9 is available on Windows Update. It fixes two vulnerabilities that were reported in time before they were publicly revealed. All of them involve remote code execution if a user visits an attacker’s Web page. The user can then gain the same rights as the user.
Users with UAC (User Account Control) enabled are better protected against attacks. The update is on Windows Update, so you don't need to take any special action if you have automatic updates enabled. Otherwise, I recommend deploying this update as soon as possible, because the most vulnerable systems are in the time between the disclosure of the vulnerability and the installation of the security update.
The update is for Internet Explorer 9 and is rated Important for Windows Client and Recommended for Windows Server.