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

Published Aug 15, 2026

Updated

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.

Affected Software

10 affected components

IBM AIX<=7.2

IBM AIX<=7.3

IBM PowerVM VIOS<=4.1

IBM AIX>=7.2.5<=7.2.5.212

IBM AIX>=7.3.2<=7.3.2.5

IBM AIX>=7.3.3<=7.3.3.2

IBM AIX>=7.3.4<=7.3.4.1

IBM VIOS>=4.1.0<4.1.0.50

IBM VIOS>=4.1.1.0<4.1.1.30

IBM VIOS>=4.1.2.0<4.1.2.20

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade IBM PowerVM VIOS 4.1.0 to a version that resolves this vulnerability.
Fixed in 4.1.0.50Patch IJ5956508/14/2026
Upgrade
Upgrade IBM PowerVM VIOS 4.1.1 to a version that resolves this vulnerability.
Fixed in 4.1.1.30Patch IJ5956408/14/2026
Upgrade
Upgrade IBM PowerVM VIOS 4.1.2 to a version that resolves this vulnerability.
Fixed in 4.1.2.20Patch IJ5956308/14/2026
Operational
For the AIX and VIOS SP/FP update, perform an LPAR reboot to complete the SP/FP update.
Operational
For VIOS 4.1.0 and VIOS 4.1.1, after applying the corresponding VIOS 4.1.0.50 or 4.1.1.30 FP, complete the additional steps required to migrate to the latest Postgres15.

Aug 15, 2026

CVE Published

via IBM·12:00 AM

Data Sourced

via IBM·12:00 AM

DescriptionAffected Software

Aug 19, 2026

CVE Published

via MITRE·07:31 PM

Data Sourced

via MITRE·07:31 PM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·08:17 PM

RemedyDescriptionSeverityWeaknessAffected Software

This vulnerability appears in the following advisories.