CVE-2026-16840 Vulnerabilities in IBM AIX and PowerVM VIOS

Critical 9.8 Published 19 Aug 2026 Updated 22 Aug 2026

A remote attacker can execute arbitrary code on IBM AIX and PowerVM VIOS systems due to an out-of-bounds write vulnerability.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-16840?

CVE-2026-16840 is a critical memory corruption vulnerability in Ibm Aix, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to execute arbitrary code due to an out-of-bounds write.

Weakness: CWE-787

Which versions are affected by CVE-2026-16840?

It affects 2 products.

Products include Ibm Aix, Ibm Vios.

How do I fix CVE-2026-16840?

No fix has been published for CVE-2026-16840 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-16840 being exploited?

There is no known exploitation of CVE-2026-16840 in the wild and no public exploit code.

All Ibm Aix vulnerabilities

Sources

Also known as GHSA-w74v-4vvf-qm9c.