External risk intelligence

IBM AIX and PowerVM Use-After-Free Vulnerability Allows Code Execution

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-17118

IBM AIX and PowerVM VIOS are server operating systems and virtualization management components typically deployed within restricted internal data center environments. While network-reachable in some specific configurations, they are not designed or commonly deployed as public-facing internet services.

Use After Free

Halo Surface Signal: 2 out of 5 — less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in IBM AIX and IBM PowerVM VIOS that could allow an unauthorized remote attacker to execute arbitrary code. This is due to a use-after-free flaw, which can be exploited over the network without requiring any privileges or user interaction. The primary concern is to confirm if these systems are present in your environment and exposed to potential threats.

Flaw allows remote code execution on IBM systems.
Critical risk: potential for unauthorized system control.
Confirm relevance and exposure within our environment.

Attack Path

How an attacker could exploit the issue

An attacker could target systems running IBM AIX or IBM PowerVM VIOS over the network without needing any special privileges. By sending specially crafted data, they could exploit a flaw where the system tries to use memory that has already been freed, potentially allowing them to run their own code on the system.

No special access required.
Crafted data triggers vulnerability.
Arbitrary code execution risk.

Live Threat

Current exploitation, exposure, and threat context

A use-after-free vulnerability in IBM AIX and IBM PowerVM VIOS could allow a remote attacker to execute arbitrary code. This means an attacker could potentially run unauthorized commands on the affected systems without needing any privileges, when supported by the advisory.

System code execution.
Network access to vulnerable systems.
Compromise of affected systems.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability impacts IBM AIX and IBM PowerVM VIOS, suggesting that infrastructure and platform teams are likely responsible for remediation. The first practical step is to identify all instances of these systems, determine their network reachability and business criticality, and then confirm the accountable owner for planning the appropriate response based on risk.

Infrastructure and platform teams own remediation.
Verify system inventory and network exposure.
Plan and coordinate remediation efforts.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is IBM AIX and PowerVM VIOS?

IBM AIX is a proprietary Unix operating system used for enterprise-level applications, while PowerVM VIOS is a virtualization management component that enables resource sharing across virtual machines. These systems are foundational for high-performance computing environments.

How does this use-after-free vulnerability work?

This vulnerability, classified as CWE-416, occurs when a program continues to reference a memory location after it has been cleared or released. If an attacker manages to place their own data into that specific memory address before the system reuses it, they can manipulate the system's logic to execute unauthorized, arbitrary code.

Do I need special access to trigger this bug?

No, this vulnerability does not require the attacker to have pre-existing user accounts or specific privileges. It is triggered by sending specially crafted network data to the affected system. Simply having network connectivity to the system is sufficient to attempt exploitation; the bug is not triggered by standard, legitimate system operations.

Why does Halo Surface Signal categorize this as unlikely to be public-facing?

According to Halo Surface Signal, IBM AIX and PowerVM VIOS are typically deployed within secure, internal data center environments to manage critical infrastructure. While they rely on network communication, they are not designed to be accessed directly from the public internet, which generally limits the pool of potential attackers.

When should I begin responding to CVE-2026-17118?

You should begin by cataloging your environment to identify all instances of IBM AIX and PowerVM VIOS. Once you have a complete inventory, assess which systems are reachable over your network and determine who is responsible for their maintenance. Prioritize these systems based on their business criticality to prepare for patching or configuration updates.

References

www.ibm.com/support/pages/node/7283858

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.