VulnerabilityDeferred

CVE-2026-11858

Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service.

HIGH 8.4EPSS 0.13%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 8.4 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.13% probability · 3th percentile
CISA KEV: Not listed
Weakness: CWE-862
Source: 551230f0-3615-47bd-b7cc-93e92e730bbf

References

https://r.sec-consult.com/quanos

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.