Microsoft .NET Core and Visual Studio could allow a remote attacker to execute arbitrary code on the system. By sending a specially crafted request, an attacker could exploit this vulnerability to execute arbitrary code on the system with elevated privileges. Exploit in the Wild.
Use Microsoft Automatic Update to apply the appropriate patch for your system, or the Microsoft Security Update Guide to search for available patches. See references https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2021-26701