After wide-spread news on vulnerability in Internet Explorer 8 that could allow remote code execution, few days back Microsoft has issued Security Advisory 2847140 to address it. IE6, IE7, Internet Explorer 9 and Internet Explorer 10 are not affected with this. Since this vulnerability has been found exploited in wild in this May that’s why if you’re using IE8 you’re recommended to upgrade to IE9 or IE10 or use the Fix It 50992 (named as CVE-2013-1347 MSHTML workaround) released by Microsoft to stay safe from attacks.
IE8 Vulnerability Details: “The vulnerability exists in the way that Internet Explorer accesses an object in memory that has been deleted or has not been properly allocated. The vulnerability may corrupt memory in a way that could allow an attacker to execute arbitrary code in the context of the current user within Internet Explorer. An attacker could host a specially crafted website that is designed to exploit this vulnerability through Internet Explorer and then convince a user to view the website.”