CVE-2026-18842
Local privilege escalation in IBM AIX and PowerVM VIOS via out-of-bounds write.
Is CVE-2026-18842 being exploited?
Not confirmed. CVE-2026-18842 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 0.11% probability of exploitation in the next 30 days.
How severe is CVE-2026-18842?
CVE-2026-18842 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-2026-18842?
Yes. A fix has been recorded for CVE-2026-18842. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-18842 affect?
CVE-2026-18842 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-2026-18842?
Apply vendor patch ASAP; restrict local access and audit privileged accounts.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can exploit an OOB write to escalate to root/system privileges, enabling 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.