You get latest build 15.0.20073.0 from https://www.microsoft.com/en-us/download/details.aspx?id=53613
Where to download sql server 2016 report builder
I have been advised to upgrade report build from 15.0.900.17 (with known vulnerabilities) to the latest version 15.0.20073.0. When I try to do this it says it needs reportbuild3.msi for sql server 2016 report builder. Of course this is long gone. Does anyone know where it can be downloaded again please.