CVE-2026-26171: Microsoft Security Advisory CVE-2026-26171 – .NET Denial of Service Vulnerability

Microsoft is releasing this security advisory to provide information about a vulnerability in System.Security.Cryptography.Xml. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A vulnerability exists in EncryptedXml class where uncontrolled resource consumption can give an attacker to the ability to perform a Denial of Service attack.