Description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to manipulate network traffic and DNS configuration due to improper authentication.
Published: 2026-08-19
Score: 8.2 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

This vulnerability allows an attacker who can reach the affected system remotely to alter network traffic patterns and change DNS settings because the system’s authentication mechanism does not properly enforce identity checks. The flaw is classified as CWE‑287 and carries a CVSS score of 8.2, indicating that successful exploitation could compromise the integrity of network communications and provide a foothold for lateral movement or interception. The potential impact includes unauthorized routing of traffic, denial of service to legitimate services, or redirection of domain resolution to malicious endpoints, thereby affecting confidentiality, integrity, and availability of services on the compromised host.

Affected Systems

The affected software includes IBM AIX versions 7.2 and 7.3 and IBM PowerVM VIOS 4.1. For AIX, remediation is available through Service Packs such as AIX 7.3 TL04 SP2, AIX 7.3 TL03 SP3, AIX 7.3 TL02 SP5, and AIX 7.2 TL05 SP13. For VIOS, Fix Packs such as VIOS 4.1.2 4.1.2.20, VIOS 4.1.1 4.1.1.30, and VIOS 4.1.0 4.1.0.50 provide cumulative fixes for all previously published vulnerabilities and can be applied to any earlier affected level of the technology line.

Risk and Exploitability

With a CVSS score of 8.2 the severity is high, although the EPSS score is not available, the lack of a KEV listing suggests no widely documented exploit yet. The attack vector is inferred to be remote, taking advantage of the improper authentication to gain the necessary privileges. Exploitation requires the ability to reach the system over the network and does not need local access. An LPAR reboot is required to finalize the update, although a Live Update can avoid downtime on AIX. Adhering to the documented secure nimsh protocol and migrating to Postgres15 for VIOS 4.1.x are recommended post‑update steps to ensure overall system integrity.

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

  • Apply the latest applicable AIX Service Pack or VIOS Fix Pack (for example, AIX 7.3 TL04 SP2 or VIOS 4.1.2 4.1.2.20) and follow the vendor’s instructions for downloading and installing the patches from Fix Central.
  • If the host is running AIX and Live Update is enabled, use Live Update to apply the patch without rebooting; otherwise, reboot the LPAR after the update to complete the service pack or fix pack installation.
  • When using nimsh secure to apply the patches, follow the special protocol steps outlined in the IBM support article to ensure secure communication between the master and client nodes.
  • For VIOS 4.1.0 and 4.1.1, after installing the recommended fix pack, perform the Postgres migration to Postgres15 using the procedures provided in the IBM support pages linked in the advisory.

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

Tracking

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Advisories

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History

Mon, 24 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

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

Type Values Removed Values Added
Metrics ssvc

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


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 manipulate network traffic and DNS configuration due to improper authentication.
Title Vulnerabilities in IBM AIX and PowerVM VIOS
First Time appeared Ibm
Ibm aix
Ibm powervm Vios
Weaknesses CWE-287
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': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: ibm

Published:

Updated: 2026-08-20T15:57:06.474Z

Reserved: 2026-07-24T03:38:04.871Z

Link: CVE-2026-16857

cve-icon Vulnrichment

Updated: 2026-08-20T15:50:14.956Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-19T20:17:07.337

Modified: 2026-08-24T16:01:09.967

Link: CVE-2026-16857

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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

Weaknesses