CVE-2026-11857: Quanos Solutions SCHEMA ST4 · Deserialization of Untrusted Data
Affects Quanos Solutions SCHEMA ST4Source CVE Database V5
Not known to be exploited · CVSS 8.4 High.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 17 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Quanos Solutions GmbHSCHEMA ST4 | Affected
| Fixed in– |
AI-suggested
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.
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.