CVE-2026-16839: CWE-125 Out-of-bounds Read in IBM AIX
Description
CVE-2026-16839 is a critical vulnerability in IBM AIX versions 7.2 and 7.3, and IBM PowerVM VIOS 4.1. It involves an integer underflow in the IPv4 IP-options parser that could allow a remote attacker to read out-of-bounds memory, potentially exposing sensitive information. The vulnerability has a high CVSS score of 9.4, indicating a severe impact on confidentiality, integrity, and availability.
CVSS v3.1
Score 9.4critical
Affected software
IBM
AIX
IBM
PowerVM VIOS
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:*:*:*:*:*:*:*Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-16839) affects IBM AIX 7.2, 7.3, and IBM PowerVM VIOS 4.1. It is caused by an integer underflow in the IPv4 IP-options parser, leading to an out-of-bounds read (CWE-125). This flaw could be exploited remotely without authentication to obtain sensitive information. The CVSS v3.1 base score is 9.4, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and impacts on confidentiality (low), integrity (high), and availability (high).
Potential Impact
A remote attacker can exploit this vulnerability to read memory outside the intended bounds, potentially leaking sensitive information. The vulnerability affects confidentiality, integrity, and availability of the affected systems. No known exploits are reported in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official patch or workaround information is provided in the available data. Monitor IBM's security advisories for updates and apply any official fixes once released.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- ibm
- Date Reserved
- 2026-07-24T02:59:13.055Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a86098facd9273b498b4bf7
Added to database: 08/19/2026, 19:52:47 UTC
Last enriched: 09/11/2026, 06:16:53 UTC
Last updated: 10/04/2026, 10:02:25 UTC
Views: 29
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