Since we already have a Lync Server 2010 Cumulative Update List it makes sense to have the same for Lync Server 2013. We can use the PowerShell cmdlet described in Lync Server Component Version to know which version is installed.
After running Lync Server Update package, not all components will be updated to the latest version – this is a normal behavior, however you can use Lync Server Core Component as reference, since this component is always updated. In case of doubt, if all components were updated, you can run the update package again or check the update logs.
In the following link you can get the latest update:
Finally, here is a list of all cumulative updates released for Lync Server 2013: