.NET 9.0.5 release carries security fixes and non-security fixes. Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 9.0.xxx and .NET 8.0.xxx SDK. This advisory also provides guidance on what developers can do to update their applications to address this vulnerability. A vulnerability exists in .NET SDK or MSBuild applications where external control of file name or path allows an unauthorized attacked to perform spoofing over a network. You need Visual Studio 17.12 or later to use .NET 9.0 on Windows. While not officially supported, we’ve also enabled rudimentary support for .NET 9 in Visual Studio for Mac.