Severity Rating: Critical - Revision Note: V1.2 (April 22, 2009): Corrected the FAQ, "Is it possible to enable the Internet Explorer defense-in-depth protection for the blended threat vulnerability on Microsoft Windows 2000" in the section, Frequently Asked Questions (FAQ) Related to This Security Update.Summary: This security update resolves four privately reported vulnerabilities and two publicly disclosed vulnerabilities in Internet Explorer. The vulnerabilities could allow remote code execution if a user views a specially crafted Web page using Internet Explorer or if a user connects to an attacker's server by way of the HTTP protocol. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

Read more at: http://www.microsoft.com/technet/security/bulletin/MS09-014.mspx?pubDate=2009-04-22