CVE-2026-69304: Microsoft Security Advisory CVE-2026-69304 – ASP.NET Core Denial of Service Vulnerability

Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core IIS out-of-process hosting and request decompression. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

The IIS Middleware for ASP.NET Core did not properly constrain decompression of certain types of request, leading to excess memory consumption and a Denial of Service.