Thus, if you download an infected MHT file, IE will know that it needs to open the MHT file with caution (at “low integrity,” in a sandbox). That severely limits this exploit’s reach.

She made changes to the document and attemtpted to save it by clicking file, save as, inside of IE, which resulted in her saving a .mht file. Is there anyway to get to the updated word doc at this ...

While that does suggest a patch is on the way, it leaves millions of users potentially vulnerable unless they either turn off Internet Explorer or point to another app that can open MHT files.