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CVE-2026-16821: CWE-134 Use of Externally-Controlled Format String in IBM AIX

0
High
VulnerabilityCVE-2026-16821cvecve-2026-16821cwe-134gcveosvghsa-6rjg-22x4-mfvpghsa
Published: 08/28/2026 (08/28/2026, 20:43:04 UTC)
Source: CVE Database V5
Vendor/Project: IBM
Product: AIX

Description

A format string vulnerability (CWE-134) exists in IBM AIX versions 7.2 and 7.3, as well as IBM PowerVM VIOS 4.1, which could allow a local attacker to gain elevated privileges. The vulnerability has a high severity with a CVSS score of 7. It requires local access with high attack complexity and no user interaction. No official patch or remediation information is currently available.

CVSS v3.1

Score 7.0high

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected software

IBM

AIX

Affected versions
=7.2=7.3

IBM

PowerVM VIOS

Affected versions
=4.1
CPE configurations (6)
cpe:2.3:a:ibm:aix:7.2:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.2.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.3:*:*:*:*:*:*:*
cpe:2.3:a:ibm:aix:7.3.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:powervm_vios:4.1:*:*:*:*:*:*:*
cpe:2.3:a:ibm:powervm_vios:4.1.0:*:*:*:*:*:*:*

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/07/2026, 15:12:16 UTC

Technical Analysis

CVE-2026-16821 is a format string vulnerability affecting IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. This vulnerability allows a local attacker to potentially escalate privileges due to improper handling of externally-controlled format strings. The CVSS 3.1 vector indicates local attack vector, high attack complexity, low privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.

Potential Impact

Successful exploitation could lead to a local attacker gaining elevated privileges on affected IBM AIX and PowerVM VIOS systems, potentially compromising system confidentiality, integrity, and availability.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary mitigation has been published at this time.

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Technical Details

Data Version
5.2
Assigner Short Name
ibm
Date Reserved
2026-07-24T02:06:36.026Z
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6a9206c1acd9273b4963cdf6

Added to database: 08/28/2026, 22:08:01 UTC

Last enriched: 09/07/2026, 15:12:16 UTC

Last updated: 10/13/2026, 18:48:17 UTC

Views: 66

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