8.4
HIGH CVSS 4.0
CVE-2026-11858
Missing authorization in Quanos SCHEMA ST4 Client Update Service allows arbitrary file overwrite as SYSTEM
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.

INFO

Published Date :

June 17, 2026, 11:50 a.m.

Last Modified :

June 17, 2026, 11:50 a.m.

Remotely Exploit :

No

Source :

SEC-VLab
Affected Products

The following products are affected by CVE-2026-11858 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 551230f0-3615-47bd-b7cc-93e92e730bbf
Solution
Restrict access to the Client Update Service's .NET Remoting interface.
  • Apply vendor patches for Quanos SCHEMA ST4.
  • Implement proper access controls for the update service.
  • Remove or restrict privileged methods if possible.
  • Monitor for unauthorized service access attempts.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-11858 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.