CVE-2026-11858
Local privilege escalation via named pipe in Quanos SCHEMA ST4 update service.
Is CVE-2026-11858 being exploited?
Not confirmed. CVE-2026-11858 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.13% probability of exploitation in the next 30 days.
How severe is CVE-2026-11858?
CVE-2026-11858 is rated High with a CVSS score of 8.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-11858?
Not known from our data. No patch reference has been recorded for CVE-2026-11858, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-11858 affect?
CVE-2026-11858 affects Quanos SCHEMA ST4 on-premises (Client Update Service). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-11858?
Patch when available; restrict local access to host.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated local user can call Update() via named pipe to write/delete files as SYSTEM.
Patch when possible
- affectedSCHEMA ST4 on-premises, all versions
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.