.NET Framework 4.5.1 RC was released in September

KB2872781 Update for the .NET Framework 3.5.1 on Windows 7 SP1 and Windows Server 2008 R2 SP1

KB2872776 The Microsoft .NET Framework 4.5.1 RC (offline package) for Windows Vista SP2, Windows 7 SP1, Windows Server 2008 SP2, Windows Server 2008 R2 SP1, Windows 8, and Windows Server 2012

KB2872775 The Microsoft .NET Framework 4.5.1 RC (web installer) for Windows Vista SP2, Windows 7 SP1, Windows Server 2008 SP2, Windows Server 2008 R2 SP1, Windows 8, and Windows Server 2012

KB2872778 The Microsoft .NET Framework 4.5.1 RC for Windows Vista SP2, Windows 7 SP1, Windows Server 2008 SP2, Windows Server 2008 R2 SP1

KB2872772 The Microsoft .NET Framework 4.5.1 RC for Windows 8, and Windows Server 2012

 

In addtion, The following hotfix KB was released for .NET Framework

KB2888303 FIX: System.Runtime.Caching.MemoryCache class does not work as expected when a .NET Framework 4.0-based web server experiences memory pressure