Auth bypass in Quanos Solutions Gmbh Schema St4

CVE-2026-11858

Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service. The update service runs as NT AUTHORITY\SYSTEM and exposes a .NET Remoting interface over a named pipe without sufficient access controls or authorization. A local authenticated low-privileged user can connect to the interface and invoke privileged update methods such as Update(). This allows arbitrary file write and delete operations with SYSTEM privileges and can be used to achieve local privilege escalation.

Vulnerability class: Broken Access Control

Published 2026-06-17 · last modified 2026-06-17.