It looks like 1.820 is available but isn't yet in the yum repos.
There is indeed a delay between when Jamie puts it onto webmin.com, and when it gets rolled out into the Virtualmin repo. I'll check with Joe though to see what the status of that is.
No sign of it in Ubuntu 12, 14, CentOs 7 or Deb 7 here.
Chaos Reigns Within, Reflect, Repent and Reboot, Order Shall Return.