KB3079904 - critical update from Microsoft

I've just had this update on our PCs. More info from MS:

Microsoft Security Bulletin MS15-078 - Critical

and

MS15-078: Vulnerability in Microsoft font driver could allow remote code execution: July 16, 2015

See also this article from InfoWorld:

Microsoft plugs gaping security hole with KB 3079904, KB 3074667

KB3079904 - critical update from Microsoft