CVE-2026-16838

Received Received - Intake

Time-of-Check to Time-of-Use Race Condition in IBM AIX and PowerVM VIOS

Publication date: 2026-08-19

Last updated on: 2026-08-19

Assigner: IBM Corporation

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-19

Last Modified

2026-08-19

Generated

2026-08-20

AI Q&A

2026-08-20

EPSS Evaluated

N/A

NVD

CVE-2026-16838

EUVD

EUVD-2026-62727

Affected Vendors & Products

Vendor	Product	Version / Range
ibm	aix	From 7.2 (inc)
ibm	aix	From 7.3 (inc)
ibm	powervm_vios	From 4.1 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-367	The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

Attack-Flow Graph

Executive Summary

This is a time-of-check to time-of-use (TOCTOU) race condition vulnerability in IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. It allows a local attacker to overwrite critical files and access sensitive information by exploiting a timing issue between checking and using a resource.

Impact Analysis

A local attacker could exploit this to overwrite important system files or steal sensitive data. This may lead to unauthorized access, system instability, or data breaches depending on the affected system's role and data stored.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches, which may violate compliance requirements under GDPR, HIPAA, or other regulations. Organizations must address it to maintain data protection and regulatory adherence.

Mitigation Strategies

Apply IBM-provided patches or updates for AIX 7.2, 7.3, and PowerVM VIOS 4.1 to address the TOCTOU race condition. Monitor IBM security advisories for fixes and restrict local user access to critical files.

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