Description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a time-of-check to time-of-use (TOCTOU) race condition.
Published: 2026-08-20
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

A time‑of‑check to time‑of‑use race condition (CWE-367) in IBM AIX 7.2 and 7.3, as well as in PowerVM VIOS 4.1, allows a local attacker to manipulate a file or resource between the check and its use. By exploiting this, the attacker can gain elevated system privileges and execute commands with higher authority, threatening the confidentiality, integrity, and availability of the host.

Affected Systems

The vulnerability affects IBM AIX versions 7.2.0 through 7.3 and all 7.3 Tool Levels, as well as IBM PowerVM VIOS 4.1, including sub‑versions 4.1.0, 4.1.1 and 4.1.2. IBM recommends applying AIX Service Pack levels SP2, SP3, SP5 or SP13, and VIOS Fix Pack releases 4.1.0.50, 4.1.1.30, and 4.1.2.20, which cumulatively contain the fix.

Risk and Exploitability

The CVSS score of 7.8 classifies this as high severity. The description indicates a local attack vector; no network‑based exploitation path is documented. The EPSS score is not available and the issue is not listed in CISA KEV. Consequently, the privilege‑escalation impact warrants urgent remediation for any affected system.

Generated by OpenCVE AI on August 21, 2026 at 01:26 UTC.

Remediation

Vendor Solution

A.  APARS IBM has assigned the following APARs to this problem: AIX LevelAPARAvailability  SPKEY7.2.5IJ5956608/14/2026SP13key_w_apar7.3.2IJ5956508/14/2026SP05key_w_apar7.3.3IJ5956408/14/2026SP03key_w_apar7.3.4IJ59563 08/14/2026SP02key_w_apar VIOS LevelAPARAvailability SPKEY4.1.0IJ5956508/14/20264.1.0.50key_w_apar4.1.1IJ5956408/14/20264.1.1.30key_w_apar4.1.2IJ5956308/14/20264.1.2.20key_w_apar B.  FIXES IBM strongly recommends addressing the vulnerability now.  AIX and VIOS fixes are available and can be downloaded from Fix Central: https://www.ibm.com/support/fixcentral  An LPAR reboot is required to complete the SP/FP update. On AIX, Live Update can be used to avoid a reboot.  IBM has assigned the following AIX Service Packs (SPs) and VIOS Fix Packs (FPs) as the remediation levels for the published vulnerabilities. AIX Level Service PackAIX 7.3 TL04SP2AIX 7.3 TL03SP3AIX 7.3 TL02SP5AIX 7.2 TL05 SP13 PowerVM VIOS LevelFix PackVIOS 4.1.2 4.1.2.20VIOS 4.1.1 4.1.1.30VIOS 4.1.0  4.1.0.50 Note: These SPs/FPs are cumulative and include fixes for all previously published AIX/VIOS security vulnerabilities. They can be applied on top of any earlier affected level of the TL . Note: To apply these patches using nimsh secure, special steps must be taken as the protocol between master and client is updated to be more secure. Please read this article: https://www.ibm.com/support/pages/node/7283157 Note: For VIOS 4.1.0 and VIOS 4.1.1, additional steps are required to migrate to the latest Postgres15 after applying the 4.1.1.30 or 4.1.0.50 FPs above. Instructions to do that can be found here:                             4.1.0.50 post-update instructions: https://www.ibm.com/support/pages/node/7283819           4.1.1.30 post-update instructions: https://www.ibm.com/support/pages/node/7283823

OpenCVE Recommended Actions

  • Download and apply the appropriate IBM AIX Service Pack (SP2, SP3, SP5, or SP13) or PowerVM VIOS Fix Pack (4.1.0.50, 4.1.1.30, or 4.1.2.20) from Fix Central to patch the TOCTOU race condition.
  • If Live Update is available, use it to install the update without rebooting; otherwise perform a system reboot after the service pack or fix pack installation to complete the update.
  • When upgrading via nimsh secure, follow IBM’s updated protocol instructions to ensure successful communication between master and client.
  • For VIOS 4.1.0 and 4.1.1, execute the post‑update migration to Postgres15 using IBM’s provided guidance (4.1.0.50 post‑update instructions and 4.1.1.30 post‑update instructions).

Generated by OpenCVE AI on August 21, 2026 at 01:26 UTC.

Tracking

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Advisories

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History

Wed, 26 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Mon, 24 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
First Time appeared Ibm vios
CPEs cpe:2.3:a:ibm:vios:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:aix:*:*:*:*:*:*:*:*
Vendors & Products Ibm vios

Thu, 20 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
Description IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a local attacker to gain elevated privileges due to a time-of-check to time-of-use (TOCTOU) race condition.
Title Vulnerabilities in IBM AIX and PowerVM VIOS
First Time appeared Ibm
Ibm aix
Ibm powervm Vios
Weaknesses CWE-367
CPEs cpe:2.3:a:ibm:aix:7.2.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.2:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.3.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.3:*:*:*:*:*:*:*
cpe:2.3:a:ibm:powervm_vios:4.1.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:powervm_vios:4.1:*:*:*:*:*:*:*
Vendors & Products Ibm
Ibm aix
Ibm powervm Vios
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Subscriptions

Ibm Aix Powervm Vios Vios
cve-icon MITRE

Status: PUBLISHED

Assigner: ibm

Published:

Updated: 2026-08-26T14:16:26.363Z

Reserved: 2026-07-24T07:36:12.992Z

Link: CVE-2026-16935

cve-icon Vulnrichment

Updated: 2026-08-24T12:18:58.032Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-20T22:17:07.817

Modified: 2026-08-26T15:16:44.950

Link: CVE-2026-16935

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T02:30:08Z

Weaknesses
  • CWE-367

    Time-of-check Time-of-use (TOCTOU) Race Condition