Auth bypass in IBM Aix

CVE-2026-16656

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to gain root privileges due to improper authentication.

Vulnerability class: Broken Authentication

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Ibm Aix — versions 7.2, 7.3
Ibm Powervm Vios — versions 4.1

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

psirt@us.ibm.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-16656?: CVE-2026-16656 is a critical-severity vulnerability in IBM Aix, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-08-19.
How severe is CVE-2026-16656?: Critical severity. CVSS v3 base score is 9.8 out of 10.