They state that there aren't any known instances of this being exploited nor have they seen any code that could exploit, merely that it is a possibility. This flaw is separate from what was found and patched a few months ago. It can only be exploited from accepting a cam invite, and unless you have a habit of accepting those from strangers it's nothing to worry about.
This is yet another flaw, however, in the version 8 series of the client. You can read more about discovery of the flaw at the McAfee security blog.