With September 2015 PU we have released security fixes for SharePoint which are offered through Microsoft Update.
For the following SharePoint products and components fixes have been released:
SharePoint 2007 Suite:
- none
SharePoint 2010 Suite:
- none
SharePoint 2013 Suite:
- SharePoint Foundation 2013
- Excel Services 2013
- Access Services 2013
- Microsoft Office Web Apps 2013
See the security bulletin MS15-099 below for more details and KB number for the relevant fixes: