High memory usage due to RING_BUFFER
Well, no, not exactly. My fault for not making the wording on that a little better.

You're using sp_BlitzFirst, and here's something similar to what you're seeing:



It's reporting CPU usage and where I found it in the DMVs - the ring buffer. The ring buffer isn't CAUSING the high CPU use.

To find queries doing high CPU use, use sp_BlitzCache @SortOrder = 'cpu'.

For more details, check out this post from Microsoft's Premier Field Engineering team on using ring buffers to track CPU usage inside SQL Server.