CVE-2026-11857 — Insecure .NET Remoting deserialization in Quanos SCHEMA ST4 Client Update Service allows local privilege escalation

Description (CNA)

Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service due to insecure deserialization in the .NET Remoting service. The service is configured with TypeFilterLevel.Full and is bound to local interfaces only through named pipes. A local authenticated attacker can connect to the local named pipe, obtain the .NET Remoting endpoint, and send specially crafted serialized objects. Successful exploitation results in arbitrary code execution in the context of the update process with NT AUTHORITY\SYSTEM privileges. Network-only exploitation is not possible and local host access with an authenticated user session is required.

Affected (CNA)

Vendor / product	Versions
Quanos Solutions GmbH / SCHEMA ST4	affected SCHEMA ST4 on-premises, all versions

CWE

CWE-502

References

https://r.sec-consult.com/quanos

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.