This update includes only security updates. Key changes include:
Security updates to Microsoft XML Core Services, SHA-1 deprecation for SSL/TLS certificates, Windows Media Player, Microsoft Graphics Component, Windows OS, Microsoft Windows PDF Library, Windows kernel-mode drivers, Microsoft Uniscribe, Windows kernel, Windows Hyper-V, Windows kernel, Windows SMB Server, Internet Information Services, and Active Directory Federation Services.
For a complete list of affected files, see KB4012213.
:ar: To Download KB4012213 from Microsoft Update Catalog
Source: https://support.microsoft.com/en-us/help/24717/windows-8-1-and-windows-server-2012-r2-update-history