CVE-2026-16840

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 an out-of-bounds write.

Analysis

AI-generated

Technical impact

An out‑of‑bounds write in the kernel code of IBM AIX and PowerVM VIOS allows an attacker to execute arbitrary code on a target system. Because the flaw can be triggered by untrusted input, a remote user may take control of the operating system, compromising confidentiality, integrity, and availability. The weakness is classified as CWE‑787.

Affected Systems

IBM AIX versions 7.2 and 7.3, and IBM PowerVM VIOS 4.1 are affected. Patches are available as AIX service packs for 7.3 TL04 SP2, TL03 SP3, TL02 SP5, and 7.2 TL05 SP13, and as VIOS fix packs for 4.1.2.20, 4.1.1.30, and 4.1.0.50. These fix packs are cumulative and can be applied to any earlier impacted level of the top‑level release.

Risk and Exploitability

The vulnerability carries a CVSS score of 9.8, indicating a critical level of risk. EPSS data is unavailable, so the current exploitation probability is unknown; however, because the flaw permits code execution, it is clearly a high‑impact threat and is not listed in CISA’s KEV catalog. The likely attack vector is remote, over the network, as the flaw can be triggered by a specially crafted input delivered to the vulnerable system. Prompt patching is essential to mitigate the scope of potential compromise.

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

  • Apply the latest IBM AIX Service Pack or PowerVM VIOS Fix Pack that contains the fix (e.g., AIX 7.3 TL04 SP2 or higher, VIOS 4.1.2.20 or higher).
  • Reboot the logical partition after installation; on AIX the Live Update option can be used to avoid a reboot.
  • If you are using VIOS 4.1.0 or 4.1.1, follow IBM’s post‑update instructions to migrate to Postgres15 after applying the fix pack.

Generated by OpenCVE AI on August 20, 2026 at 12:09 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 an out-of-bounds write.
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, 3:01 AM
Status
Analyzed
Published
Aug 19, 2026, 8:17 PM
Modified
Oct 26, 2026, 10:10 AM