CVE-2026-16838: Vulnerabilities in IBM AIX and PowerVM VIOS

Q: Is IBM PowerVM VIOS affected as well as IBM AIX?

Yes. The affected software list includes both IBM AIX and IBM PowerVM VIOS.

Q: Does exploitation require local access?

The issue is described as exploitable by a local attacker. The provided information does not identify a remote exploitation path.

Published Aug 15, 2026

Updated

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to overwrite critical files and obtain sensitive information due to a time-of-check to time-of-use (TOCTOU) race condition.

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

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade IBM AIX to a version that resolves this vulnerability.
Patch SPKEY7.2.5I
Upgrade
Upgrade IBM PowerVM VIOS to a version that resolves this vulnerability.
Fixed in 4.1.0.50
Upgrade
Upgrade IBM PowerVM VIOS to a version that resolves this vulnerability.
Fixed in 4.1.1.30
Upgrade
Upgrade IBM PowerVM VIOS to a version that resolves this vulnerability.
Fixed in 4.1.2.20
Operational
Reboot the LPAR to complete the SP/FP update (LPAR reboot is required to complete the SP/FP update).
Operational
For VIOS 4.1.0.50 and VIOS 4.1.1.30: perform additional steps to migrate to the latest Postgres15 after applying the 4.1.1.30 or 4.1.0.50 FPs.

Event History

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·07:30 PM

Data Sourced

via MITRE·07:30 PM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·08:17 PM

RemedyDescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

IBM-7283858

Frequently Asked Questions

Is IBM PowerVM VIOS affected as well as IBM AIX?

Yes. The affected software list includes both IBM AIX and IBM PowerVM VIOS.

Does exploitation require local access?

The issue is described as exploitable by a local attacker. The provided information does not identify a remote exploitation path.

CVE-2026-16838: Vulnerabilities in IBM AIX and PowerVM VIOS

Affected Software

Remediation

Event History

Parent advisories

Frequently Asked Questions

Is IBM PowerVM VIOS affected as well as IBM AIX?

Does exploitation require local access?

Company

Resources

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