A remote code execution vulnerability exists when the Microsoft XML Core Services MSXML parser processes user input. An attacker who successfully exploited the vulnerability could run malicious code remotely to take control of the user’s system. To exploit the vulnerability, an attacker could host a specially crafted website designed to invoke MSXML through a web browser. However, an attacker would have no way to force a user to visit such a website. Instead, an attacker would typically have to convince a user to either click a link in an email message or instant message that would then take the user to the website. When Internet Explorer parses the XML content, an attacker could run malicious code remotely to take control of the user’s system. The update addresses the vulnerability by correcting how the MSXML parser processes user input.