CVE-2026-11857: CWE-502 Deserialization of untrusted data in Quanos Solutions GmbH SCHEMA ST4
Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in its Client Update Service due to insecure deserialization in the .NET Remoting service. The service uses TypeFilterLevel.Full and is accessible only via local named pipes. An authenticated local attacker can exploit this by sending crafted serialized objects, resulting in arbitrary code execution with SYSTEM privileges. Network exploitation is not possible, and local authenticated access is required.
AI Analysis
Technical Summary
CVE-2026-11857 describes a vulnerability in Quanos Solutions GmbH SCHEMA ST4 on-premises product where the Client Update Service improperly deserializes untrusted data via the .NET Remoting service configured with TypeFilterLevel.Full. The service is bound to local interfaces through named pipes only, preventing remote exploitation. A local attacker with authentication can connect to the named pipe endpoint and send malicious serialized objects, leading to arbitrary code execution with NT AUTHORITY\SYSTEM privileges, effectively escalating local privileges.
Potential Impact
Successful exploitation allows a local authenticated attacker to execute arbitrary code with SYSTEM-level privileges on the affected host. This represents a significant local privilege escalation risk. Remote exploitation over the network is not possible, limiting the attack vector to local authenticated users only.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict local access to the named pipe interfaces used by the Client Update Service to trusted users only. Monitor for any vendor updates or advisories regarding patches or mitigations.
CVE-2026-11857: CWE-502 Deserialization of untrusted data in Quanos Solutions GmbH SCHEMA ST4
Description
Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in its Client Update Service due to insecure deserialization in the .NET Remoting service. The service uses TypeFilterLevel.Full and is accessible only via local named pipes. An authenticated local attacker can exploit this by sending crafted serialized objects, resulting in arbitrary code execution with SYSTEM privileges. Network exploitation is not possible, and local authenticated access is required.
CVSS v4.0
Score 8.4high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-11857 describes a vulnerability in Quanos Solutions GmbH SCHEMA ST4 on-premises product where the Client Update Service improperly deserializes untrusted data via the .NET Remoting service configured with TypeFilterLevel.Full. The service is bound to local interfaces through named pipes only, preventing remote exploitation. A local attacker with authentication can connect to the named pipe endpoint and send malicious serialized objects, leading to arbitrary code execution with NT AUTHORITY\SYSTEM privileges, effectively escalating local privileges.
Potential Impact
Successful exploitation allows a local authenticated attacker to execute arbitrary code with SYSTEM-level privileges on the affected host. This represents a significant local privilege escalation risk. Remote exploitation over the network is not possible, limiting the attack vector to local authenticated users only.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict local access to the named pipe interfaces used by the Client Update Service to trusted users only. Monitor for any vendor updates or advisories regarding patches or mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- SEC-VLab
- Date Reserved
- 2026-06-10T09:08:22.916Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a32971a0b89be68884c1f99
Added to database: 06/17/2026, 12:46:18 UTC
Last enriched: 06/24/2026, 16:36:36 UTC
Last updated: 08/01/2026, 07:17:58 UTC
Views: 76
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