CVE-2026-42899: Microsoft Security Advisory CVE-2026-42899 – ASP.NET Core Denial of Service Vulnerability

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

Loop with unreachable exit condition (‘infinite loop’) in ASP.NET Core allows an unauthorized attacker to deny service over a network.