Vulnerability · Published Jun 17, 2026 · Assigned by SEC-VLab
CVE-2026-11857Insecure .NET Remoting deserialization in Quanos SCHEMA ST4 Client Update Service allows local privilege escalation
High 8.4
In plain English
A high-severity unsafe deserialization in SCHEMA ST4 from Quanos Solutions GmbH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Official description
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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Quanos Solutions GmbH | SCHEMA ST4 | SCHEMA ST4 on-premises, all versions |
Weakness: CWE-502 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N