Update security issue reporting instructions (#64491)

Author: danroth27

README.md

@@ -29,7 +29,9 @@ and make pull-requests.
 
 ## Reporting security issues and bugs
 
-Security issues and bugs should be reported privately, via email, to the Microsoft Security Response Center (MSRC)  [email protected]. You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your original message. Further information, including the MSRC PGP key, can be found in the [Security TechCenter](https://technet.microsoft.com/en-us/security/ff852094.aspx).
+Security issues and bugs should be reported privately to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). You should receive a response within 24 hours. Further information can be found in the [MSRC Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue). You can also find these instructions in this repo's [Security doc](SECURITY.md).
+
+Also see info about related [Microsoft .NET Bounty Program](https://www.microsoft.com/msrc/bounty-dot-net-core).
 
 ## Related projects
 

SECURITY.md

@@ -6,9 +6,9 @@ The .NET Core and ASP.NET Core support policy, including supported versions can
 
 ## Reporting a Vulnerability
 
-Security issues and bugs should be reported privately, via email, to the Microsoft Security Response Center (MSRC) through https://msrc.microsoft.com or by emailing [email protected]. 
-You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your 
-original message. Further information, including the MSRC PGP key, can be found in the [MSRC Report an Issue FAQ](https://www.microsoft.com/en-us/msrc/faqs-report-an-issue).
+Security issues and bugs should be reported privately to the Microsoft Security Response Center (MSRC), via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new).
+You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your
+original message. Further information can be found in the [MSRC Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).
 
 Reports via MSRC may qualify for the .NET Core Bug Bounty. Details of the .NET Core Bug Bounty including terms and conditions are at [https://aka.ms/corebounty](https://aka.ms/corebounty).