CVE-2026-50528: Microsoft Security Advisory CVE-2026-50528 – .NET Security Feature Bypass Vulnerability

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET TLS/SSL (System.Net.Security). This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A security feature bypass vulnerability exists in .NET 8, .NET 9, and .NET 10 when processing TLS/SSL connections. An attacker can exploit the SslStream implementation to bypass authorization checks during secure communication.