Microsoft has released CU6 for Lync Server 2010. The best way to update your Lync server is to use the Lync Server Update Installer (LyncServerUpdateInstaller.exe).

For more details on this rollup: http://support.microsoft.com/kb/2493736

List of server roles and the updates that apply to them

Lync Server 2010 – Standard Edition Server

  • Update for Core Components – KB 2701663
  • Update for Conferencing Server – KB 2575870
  • Update for Web Components Server – KB 2710559
  • Update for Standard/Enterprise edition Server – KB 2571546
  • Update for Web Conferencing Server – KB 2708616
  • Update for Conferencing Attendant – KB 2701659
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Enterprise Edition – Front-end

  • Update for Core Components – KB 2701663
  • Update for Conferencing Server – KB 2575870
  • Update for Web Components Server – KB 2710559
  • Update for Standard/Enterprise edition Server – KB 2571546
  • Update for Web Conferencing Server – KB 2708616
  • Update for Conferencing Attendant – KB 2701659
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Enterprise Edition – Stand-alone A/V Conferencing Server

  • Update for Core Components – KB 2701663
  • Update for Conferencing Server – KB 2575870
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Monitoring Server

  • Update for Core Components – KB 2701663
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Edge Server

  • Update for Core Components – KB 2701663
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Stand-alone Mediation Server

  • Update for Core Components – KB 2701663
  • Update for Mediation Server – KB 2502810
  • Update for Unified Communications Managed API 3.0 Runtime – KB 2571505

Lync Server 2010 – Administration Tools – Topology Builder

  • Update for Core Components – KB 2701663
  • Update for Administration Tools – KB 2670358