The product group released the April 2013 Cumulative Update for the SharePoint 2013 product family.
Be aware that all Update for SharePoint 2013 require March 2013 PU for SharePoint 2013 to be installed first.
The KB articles for April CU will be availabe at the following locations in a couple of days:
The Full Server Packages for April 2013 CU are available through the following links:
An up to date list provided by Microsoft could be found here.