Microsoft released the quarterly servicing update to Exchange Server 2013 – CU6 and updated UM Language Packs. Cumulative Update 6 includes significant improvements in Public Folder scalability and a fix for the HCW issue described in KB2988229. You can read the full blog post at the Exchange Team Blog.
A complete list of reported issues in Exchange Server 2013 CU6 can be found in the Knowledge Base Article KB2961810.
Download Cumulative Update 6 for Exchange Server 2013 (KB2961810).