As if you didn't need any other reasons to ditch Internet Explorer and look at an alternate. Microsoft has confirmed that every single version of IE is affected by this zero day vulnerability.
The vulnerability is a remote code execution vulnerability. 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.
Microsoft are currently investigating and will likely release a patch as soon as they can but in the meantime you can install another browser or, if that isn't an option follow the workaround steps in the source.
However, something to be aware of is now that Windows XP is not being supported anymore this patch will not be released for the OS. Food for thought.