What is CVE-2026-16816?

CVE-2026-16816 is a critical-severity vulnerability in IBM Aix, classified under OS Command Injection. CVSS score: 9.9/10. Published 2026-08-19.

How severe is CVE-2026-16816?

Critical severity. CVSS v3 base score is 9.9 out of 10.

RCE in IBM Aix

CVE-2026-16816

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote authenticated attacker to execute arbitrary commands due to improper neutralization of special elements used in an OS command.

Vulnerability class: Command Injection (OS Command Injection)

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

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (54.9th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.003

Affected products

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

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

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

Frequently asked questions

What is CVE-2026-16816?: CVE-2026-16816 is a critical-severity vulnerability in IBM Aix, classified under OS Command Injection. CVSS score: 9.9/10. Published 2026-08-19.
How severe is CVE-2026-16816?: Critical severity. CVSS v3 base score is 9.9 out of 10.