What is CVE-2026-16819?

CVE-2026-16819 is a high-severity vulnerability in IBM Aix, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.7/10. Published 2026-08-19.

How severe is CVE-2026-16819?

High severity. CVSS v3 base score is 7.7 out of 10.

Vulnerability in IBM Aix

CVE-2026-16819

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to cause a denial of service and compromise data integrity due to a time-of-check time-of-use race condition.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

Published 2026-08-19 · last modified 2026-08-21.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.6th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

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

Weakness classification (CWE)

CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

References

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

Frequently asked questions

What is CVE-2026-16819?: CVE-2026-16819 is a high-severity vulnerability in IBM Aix, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.7/10. Published 2026-08-19.
How severe is CVE-2026-16819?: High severity. CVSS v3 base score is 7.7 out of 10.