It has been a while since the last update from Microsoft. In August 2019 we got CU-10. And for a some days ago we got the CU-11. Microsoft made it public the 13th May 2020.
You will find it here: https://www.microsoft.com/en-us/download/details.aspx?id=47690
I have not tested it yet since most of my customers has moved to Teams with telephony.