Description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an out-of-bounds read.
Published: 2026-08-19
Score: 4.8 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability allows a remote attacker to trigger an out-of-bounds read within IBM AIX 7.2 and 7.3, and IBM PowerVM VIOS 4.1. This condition can cause a denial of service by crashing affected processes or destabilizing the operating environment. The flaw is an out‑of‑bounds read as identified by CWE‑125.

Affected Systems

Affected systems are IBM AIX 7.2 and 7.3, as well as IBM PowerVM VIOS 4.1. IBM recommends applying the Service Pack levels listed in the advisory: AIX 7.3 TL04 SP2, AIX 7.3 TL03 SP3, AIX 7.3 TL02 SP5, AIX 7.2 TL05 SP13 for AIX, and VIOS Fix Pack levels 4.1.2 4.1.2.20, 4.1.1 4.1.1.30, and 4.1.0 4.1.0.50 for VIOS. These are cumulative and include fixes for all previously published vulnerabilities.

Risk and Exploitability

The CVSS score is 4.8, indicating moderate severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalog. Attacks are likely remote; no public exploits are reported. The patching process requires an LPAR reboot, although AIX Live Update can avoid a reboot. The exploit would require the attacker to trigger the out‑of‑bounds read, leading to a service interruption.

Generated by OpenCVE AI on August 20, 2026 at 11:57 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 install the appropriate AIX Service Pack or VIOS Fix Pack from IBM Fix Central following the official installation guide.
  • Apply the patch using nimsh‑secure, taking care to follow the updated protocol steps outlined in IBM’s documentation.
  • For VIOS 4.1.0 or 4.1.1, after the FP is applied, use the provided post‑update instructions to migrate to Postgres15 per IBM’s guidance.

Generated by OpenCVE AI on August 20, 2026 at 11:57 UTC.

Tracking

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Advisories

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History

Thu, 20 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Thu, 20 Aug 2026 16:15:00 +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

Wed, 19 Aug 2026 19:45:00 +0000

Type Values Removed Values Added
Description IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to an out-of-bounds read.
Title Vulnerabilities in IBM AIX and PowerVM VIOS
First Time appeared Ibm
Ibm aix
Ibm powervm Vios
Weaknesses CWE-125
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': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}

Subscriptions

Ibm Aix Powervm Vios Vios
cve-icon MITRE

Status: PUBLISHED

Assigner: ibm

Published:

Updated: 2026-08-20T15:57:06.167Z

Reserved: 2026-07-24T04:11:52.991Z

Link: CVE-2026-16866

cve-icon Vulnrichment

Updated: 2026-08-20T15:50:02.628Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-19T20:17:07.967

Modified: 2026-08-20T16:17:12.927

Link: CVE-2026-16866

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-20T12:00:04Z

Weaknesses