See release notes:
https://github.com/Microsoft/ChakraCore/wiki/Roadmap#v123

Also available on NuGet:
https://www.nuget.org/packages/Microsoft.ChakraCore/1.2.3

See ChakraCore Wiki: NuGet Packages for more info.

The attached ChakraCore-binaries.zip includes Microsoft-signed binaries corresponding to this release. Contents of this archive are as follows:

arm
    ch.exe
    ch.pdb
    ChakraCore.dll
    ChakraCore.pdb
x64
    ch.exe
    ch.pdb
    ChakraCore.dll
    ChakraCore.pdb
x86
    ch.exe
    ch.pdb
    ChakraCore.dll
    ChakraCore.pdb