CVE-2026-11858

CVE-2026-11858 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-862.

Key facts

Description

Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service. The update service runs as NT AUTHORITY\SYSTEM and exposes a .NET Remoting interface over a named pipe without sufficient access controls or authorization. A local authenticated low-privileged user can connect to the interface and invoke privileged update methods such as Update(). This allows arbitrary file write and delete operations with SYSTEM privileges and can be used to achieve local privilege escalation.

Frequently asked questions

What is CVE-2026-11858?
Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service. The update service runs as NT AUTHORITY\SYSTEM and exposes a .NET Remoting interface over a named pipe without sufficient access controls or authorization. A local authenticated low-privileged user can connect to the interface and invoke privileged update methods such as Update(). This allows arbitrary file write and delete operations with SYSTEM privileges and can be used to achieve local privilege escalation.
How severe is CVE-2026-11858?
CVE-2026-11858 has a CVSS 4.0 base score of 8.4, rated high severity.
Is CVE-2026-11858 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-11858?
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-2026-11858 have an EU (EUVD) identifier?
Yes. CVE-2026-11858 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37682.
When was CVE-2026-11858 published?
CVE-2026-11858 was published on 2026-06-17.

References

Other CWE-862 (Missing Authorization) vulnerabilities

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