CVE-2026-18808
Critical code-injection in Klemsan KIO (<v1.9) enabling remote code execution.
Is CVE-2026-18808 being exploited?
Not confirmed. CVE-2026-18808 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 0.39% probability of exploitation in the next 30 days.
How severe is CVE-2026-18808?
CVE-2026-18808 is rated Critical with a CVSS score of 9.8. 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-2026-18808?
Yes. A fix has been recorded for CVE-2026-18808. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-18808 affect?
CVE-2026-18808 affects Klemsan KIO (Klemsan Internet Objects) firmware < v1.9, Klemsan IoT controllers, Devices running KIO runtime. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-18808?
Immediately upgrade KIO to v1.9, isolate devices, apply vendor mitigations and monitor.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution via code injection; enables full device takeover, firmware compromise, persistent backdoors and lateral network pivoting.
Immediate action required
- affected< v1.9
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.