Don't know that we have a formal announcement on an MS site yet, but there is some info on the possible issues here: http://myitforum.com/myitforumwp/2013/07/13/cm-issues-with-ms13-052-kb2840628. This affects CM2007 and CM2012.
If you have issues with KB2840628 open a case with Premier Support. And this just reinforces something I preach to my customers all the time: You need a separate test lab that mirrors your production environment and you need to test everything in there (updates, images, packages, etc). And testing in production is not testing :-)