Windows 10 Windows 10 High CPU/High Memory in WSUS following Update Tuesdays.

[kemical]

Microsoft have recently identified issues with high cpu and high memory usage in certain Windows 10 builds (1703 isn't affected... Yet. ).

Builds which are affected are: Windows 10 version's 1607, 1511, and 1507.
Apparently this is down to recent updates which are named in the quote's below:

Recently, we’ve seen an increase in the number of high CPU/High Memory usage problems with WSUS, including WSUS in a System Center Configuration Manager environment – these have mostly corresponded with Update Tuesdays.

So if your currently running one of the above builds you might be experiencing higher levels of CPU and RAM use.
Microsoft does go on to say that it's currently investigating

Microsoft support has determined that the issue is driven primarily by the Windows 10 1607 updates, for example KB4022723, KB4022715, KB4025339, etc. See here for the list of Windows 10 1607 updates.

Microsoft is also aware of a known issue with KB4034658 that will cause Windows 10 1607 clients to run a full scan after install – Microsoft is investigating and the latest information is available here.

These updates have large metadata payloads for the dependent (child) packages because they roll up a large number of binaries. Windows 10, versions 1507 (Windows 10 RTM) and 1511 updates can also cause this, though to a lesser extent. Windows 10, version 1703 is still recent enough that the metadata is not that large yet (but will continue to grow).

The WSUS team is investigating improvements to metadata processing. We will update this blog when as updates become available.

Ref:
High CPU/High Memory in WSUS following Update Tuesdays