External risk intelligence

Linux Kernel iwlwifi MLD TSO Segmentation Exploit

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64037

This vulnerability exists within the Linux kernel's wireless driver (iwlwifi) and specifically concerns internal memory management and frame segmentation during hardware-level transmit processing. It is a low-level driver component that is not directly exposed to the internet or reachable by remote network traffic in typical deployments.

Use After Free

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in the Linux kernel's wireless driver could allow for the creation of an excessive number of tiny data segments, potentially leading to memory corruption and issues with network data transmission. While the direct impact on business operations is unlikely due to the specific technical nature of the flaw and its internal processing, confirming its relevance to your environment is prudent.

Affects internal wireless driver processing.
Confirm relevance, as direct business impact is unlikely.
Low-level technical issue, not a direct threat.

Attack Path

How an attacker could exploit the issue

An attacker could leverage a specific condition within the Linux kernel's wireless driver to cause a segmentation explosion. This leads to an excessive number of tiny data segments being generated, which can overwhelm the system's transmission processing. This can ultimately result in memory corruption and a use-after-free vulnerability within the TCP retransmission logic.

Network access required.
Vulnerable kernel component triggered.
Memory corruption and use-after-free.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an attacker to cause a denial-of-service condition by overwhelming the system with network transmission events. This occurs when specific conditions related to Wi-Fi frame segmentation are met, potentially leading to memory corruption and system instability.

Network traffic processing.
Flooding the system with transmit events.
System instability or denial-of-service.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability resides in the Linux kernel's wireless networking driver (iwlwifi). Responsibility for addressing this issue likely falls to the infrastructure or platform teams managing the kernel, with potential coordination needed from network and security teams to assess exposure. The first practical step is to identify systems running the affected kernel version and determine their network reachability and criticality.

Infrastructure or platform teams own resolution.
Verify affected kernel and system exposure.
Plan remediation during maintenance windows.

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 the Linux kernel iwlwifi driver?

The iwlwifi driver is a component within the Linux kernel that manages communication for Intel wireless network adapters. It translates software networking requests into the specific signals required for hardware to send and receive data over Wi-Fi, handling complex tasks like frame aggregation and segmentation to optimize performance.

What kind of vulnerability is CVE-2026-64037?

This is a logic error in how the driver handles data segmentation when a specific performance feature, AMSDU, is disabled. The driver incorrectly calculates packet sizes, leading to a 'segmentation explosion' where a single transmission is split into tens of thousands of tiny fragments, ultimately overwhelming the system's memory and causing critical stability failures.

How is this TSO segmentation flaw triggered?

The issue is triggered when the system disables AMSDU for a specific traffic stream, causing the driver to enter an undefined state. Normal traffic processing without this specific configuration change does not trigger the bug. It requires the driver to reach a flawed calculation path that creates a zero-sized segment, which then propagates through the network stack.

Do I need to worry about this vulnerability?

Halo Surface Signal indicates that this is unlikely to be a direct risk because the vulnerability exists deep within the kernel's wireless driver and is not directly exposed to or reachable by typical remote network traffic. It is an internal driver-level processing issue rather than a standard service-level vulnerability.

When should I update my systems for this CVE?

Since this involves low-level kernel drivers, your infrastructure or platform team should first verify which systems are running the affected kernel versions. Once identified, you should plan to apply the official kernel patches during your next scheduled maintenance window to ensure stability, rather than treating this as an emergency external threat.

References

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.