CVE-2026-16864

Vulnerabilities in IBM AIX and PowerVM VIOS

Published Aug 19, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to execute arbitrary code due to a stack buffer overflow.

Analysis

AI-generated

Technical impact

IBM AIX 7.2, AIX 7.3, and PowerVM VIOS 4.1 suffer a stack buffer overflow that can be triggered by a remote attacker to execute arbitrary code with the privileges of the affected process. The flaw is identified as CWE-787 and carries a CVSS score of 9.8, indicating very high severity. An attacker who can reach the vulnerable side of the system could compromise the confidentiality, integrity, or availability of the affected platform.

Affected Systems

The vulnerability affects IBM AIX versions 7.2 and 7.3 as well as IBM PowerVM VIOS 4.1. For AIX, service packs AIX 7.3 TL04 SP2, AIX 7.3 TL03 SP3, AIX 7.3 TL02 SP5, and AIX 7.2 TL05 SP13 contain the fix. For VIOS, the relevant Fix Packs are VIOS 4.1.2 FP 4.1.2.20, VIOS 4.1.1 FP 4.1.1.30, and VIOS 4.1.0 FP 4.1.0.50.

Risk and Exploitability

The CVSS score of 9.8 reflects a high likelihood of a successful exploitation once the conditions are met. No EPSS score is available, but the absence of a KEV listing does not reduce the risk. The overflow can be exploited remotely, typically from over network interfaces or management channels that provide access to the vulnerable process. An attacker does not need local privilege escalation, and the stack corruption allows arbitrary code execution. The required action involves applying the VN service packs and fix packs, rebooting, and performing any necessary post‑update migration steps.

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 latest AIX Service Pack (e.g., AIX 7.3 TL04 SP2 or newer) and VIOS Fix Pack (e.g., VIOS 4.1.2 FP 4.1.2.20 or newer) from IBM Fix Central.
  • Reboot the LPAR to complete the installation; for AIX Live Update can be used to avoid a reboot, and for VIOS 4.1.0 or 4.1.1 follow IBM's post‑update migration to Postgres 15 using the provided guides.
  • Update or reconfigure nimsh secure to ensure the master–client protocol uses the latest security settings, following IBM’s security update article.

Generated by OpenCVE AI on August 20, 2026 at 11:59 UTC.

Tracking

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Advisories

No advisories available
History
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
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

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 execute arbitrary code due to a stack buffer overflow.
Title Vulnerabilities in IBM AIX and PowerVM VIOS
First Time appeared Ibm
Ibm aix
Ibm powervm Vios
Weaknesses CWE-787
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': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ibm
Published
Updated
Aug 22, 2026, 3:55 AM
Reserved
Jul 24, 2026, 4:06 AM
Status
Analyzed
Published
Aug 19, 2026, 8:17 PM
Modified
Oct 26, 2026, 10:10 AM