Some .NET Core security advisories have been published this past week. You can find more details in the following blog post
If you have existing applications using previous versions of the .NET Core SDK, then please read the actual advisories (here
) to understand how to fix those applications.
And most importantly
, for ASP.NET Core you need to go through the information in security advisories CVE-2018-0785
there are changes required to your actual source code.