With the November Cumulative Security Update for Internet Explorer, the build number of Microsoft's browser has bumped to 9.0.11. This security update resolves three privately reported vulnerabilities in Internet Explorer. The vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user.
If you have enabled automatic updating then you do not need to take any action. If you haven't, then launch Windows Update from the start menu.