Tianocore, not the UEFI Forum, has released UDK2018, the latest UEFI Dev Kit, a snapshot of the EDK-II, tied to particular revision of the specs.
https://github.com/tianocore/tianocore.github.io/wiki/UDK2018-Core-Update-Notes
https://github.com/tianocore/tianocore.github.io/wiki/UDK2018-Key-Features
https://github.com/tianocore/tianocore.github.io/wiki/UDK2018
https://github.com/tianocore/edk2/releases/tag/vUDK2018
https://github.com/tianocore-docs/Docs/blob/master/UDK/UDK2018/SecurityPkgNotes.md