CVE-2026-11857
CVE-2026-11857 is a high-severity vulnerability with a CVSS 4.0 base score of 8.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.
Key facts
- Severity: High (CVSS 4.0 base score 8.4)
- EPSS exploit prediction: 0% (19th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-37681
- Weakness: CWE-502
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-11857?
- 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.
- How severe is CVE-2026-11857?
- CVE-2026-11857 has a CVSS 4.0 base score of 8.4, rated high severity.
- Is CVE-2026-11857 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-11857?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-11857 have an EU (EUVD) identifier?
- Yes. CVE-2026-11857 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37681.
- When was CVE-2026-11857 published?
- CVE-2026-11857 was published on 2026-06-17.
References
Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities
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