What is CVE-2026-16686?

CVE-2026-16686 is a high-severity vulnerability in IBM Aix, classified under Improper Authentication. CVSS score: 8.2/10. Published 2026-08-19.

How severe is CVE-2026-16686?

High severity. CVSS v3 base score is 8.2 out of 10.

Auth bypass in IBM Aix

CVE-2026-16686

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to access NFS-exported filesystems due to improper authentication.

Vulnerability class: Broken Authentication

Published 2026-08-19 · last modified 2026-08-20.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (40.8th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

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

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

www.ibm.com/support/pages/node/7283858 (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-16686?: CVE-2026-16686 is a high-severity vulnerability in IBM Aix, classified under Improper Authentication. CVSS score: 8.2/10. Published 2026-08-19.
How severe is CVE-2026-16686?: High severity. CVSS v3 base score is 8.2 out of 10.