CVE-2026-18840
Local arbitrary code execution in IBM AIX and PowerVM VIOS
Is CVE-2026-18840 being exploited?
Not confirmed. CVE-2026-18840 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 0.12% probability of exploitation in the next 30 days.
How severe is CVE-2026-18840?
CVE-2026-18840 is rated High with a CVSS score of 8.2. 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-2026-18840?
Yes. A fix has been recorded for CVE-2026-18840. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-18840 affect?
CVE-2026-18840 affects IBM AIX 7.2, IBM AIX 7.3, IBM PowerVM VIOS 4.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-18840?
Apply vendor patch/updates when available; restrict local access and monitor system logs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can execute arbitrary code via a crafted pointer, enabling privilege escalation and potential full host compromise.
Patch when possible
- affected7.2
- affected7.3
- affected4.1
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.