Description
IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to obtain sensitive information due to an integer underflow in the IPv4 IP-options parser.
Published: 2026-08-19
Score: 9.4 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability is an integer underflow in the IPv4 IP‑options parser that allows a remote attacker to read sensitive data. The flaw can be triggered by carefully crafted packet options and results in disclosure of information that should be protected, potentially including configuration or content stored in memory. The weakness is classified as CWE‑125, an underflow condition that corrupts size calculations.

Affected Systems

IBM AIX releases 7.2 and 7.3 are vulnerable when they have not been updated to the Service Packs listed in the advisory. IBM PowerVM VIOS 4.1 is affected until the latest Fix Packs are applied. All earlier AIX 7.2.x and 7.3.x Service Packs, as well as VIOS 4.1.x releases, remain at risk until the recommended updates are installed.

Risk and Exploitability

The CVSS score of 9.4 indicates a high severity, and the vulnerability is exploitable from a remote network without authentication. EPSS is not available, but the lack of a KEV listing does not diminish the risk; an attacker with network access can send malicious IP‑options packets to trigger the underflow and extract data. IBM strongly recommends immediate installation of the specified SPs/FPs; failure to do so exposes systems to potential data exposure.

Generated by OpenCVE AI on August 20, 2026 at 12:14 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 latest AIX Service Pack (SP2 for AIX 7.3 TL04, SP3 for AIX 7.3 TL03, SP5 for AIX 7.3 TL02, or SP13 for AIX 7.2 TL05) from IBM Fix Central or use Live Update to avoid a reboot
  • Download and install the corresponding PowerVM VIOS Fix Pack (4.1.2.20 for VIOS 4.1.2, 4.1.1.30 for VIOS 4.1.1, or 4.1.0.50 for VIOS 4.1.0), then reboot the LPAR to complete the update
  • For VIOS 4.1.0 and 4.1.1, follow IBM’s post‑update instructions to migrate to Postgres 15; apply the migration steps linked in the advisory before using the system

Generated by OpenCVE AI on August 20, 2026 at 12:14 UTC.

Tracking

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Advisories

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History

Mon, 24 Aug 2026 16:00:00 +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 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, '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 obtain sensitive information due to an integer underflow in the IPv4 IP-options parser.
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': 9.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H'}

Subscriptions

Ibm Aix Powervm Vios Vios
cve-icon MITRE

Status: PUBLISHED

Assigner: ibm

Published:

Updated: 2026-08-20T12:31:40.524Z

Reserved: 2026-07-24T02:59:13.055Z

Link: CVE-2026-16839

cve-icon Vulnrichment

Updated: 2026-08-20T12:31:34.654Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-19T20:17:05.030

Modified: 2026-08-24T15:54:29.040

Link: CVE-2026-16839

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-20T12:15:03Z

Weaknesses