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Insecure .NET Remoting deserialization in Quanos SCHEMA ST4 Client Update Service allows local privilege escalation

Microsoft .NET · CVE-2026-11857
0 news outlets0 CERTs and agencies0 researchers

Assessment: Track

SSVC decision points: exploitation none, automatable no, technical impact total, deployment high.

What is it?

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.

Evidence

Technical advisories (1)
Detailed write-ups from security research teams

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
8.4
EPSS
0.3%
First seen
1 h ago
Status
confirmed

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