External risk intelligence

Linux Kernel ixgbevf Use-After-Free in Multicast Pruning

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64113

This vulnerability exists within a Linux kernel driver for specific network interface hardware (ixgbevf). It occurs during internal packet processing within the kernel's NAPI softirq context. This is a low-level driver memory management issue, not an internet-facing service, application, or protocol endpoint, and is not directly reachable or exploitable from the public internet.

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 security vulnerability has been identified in a specific Linux kernel driver that handles network interface communication. This issue, stemming from a memory management error, could potentially allow for unauthorized access or manipulation of system resources if exploited. While the immediate impact is unclear, verifying its relevance to our environment is the primary concern.

Affects a specific Linux network driver.
Requires confirming relevance and exposure.
Assess potential impact on infrastructure.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by triggering a specific condition within the Linux kernel's network driver. This condition involves a race between freeing and re-accessing memory used for network packet processing, potentially leading to system instability or code execution. The vulnerability lies in how the `ixgbevf` driver handles incoming network frames.

Network packet processing error.
Use-after-free in interrupt handler.
System instability or code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could affect the internal memory management of the Linux kernel's network driver when processing specific network packets. When supported by the advisory, it could lead to the kernel attempting to use memory that has already been freed, potentially impacting the stability and integrity of network operations.

Kernel network packet data.
Use-after-free in driver processing.
System instability or crashes.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Linux kernel's `ixgbevf` driver has a use-after-free vulnerability that could allow an attacker to gain control of the system. Identifying systems running this driver, confirming exposure and criticality, and then coordinating with the Linux kernel development team or your distribution vendor for a fix is the primary initial step.

Infrastructure teams own the kernel.
Verify exposure and criticality of systems.
Plan for kernel updates during maintenance.

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 ixgbevf driver in the Linux kernel?

The ixgbevf driver is a component of the Linux kernel responsible for managing communication for specific network interface hardware, specifically Virtual Function (VF) drivers for Intel 10 Gigabit Ethernet adapters. It handles the low-level processing of incoming and outgoing network data packets between the hardware and the host operating system.

What does this use-after-free vulnerability mean?

This is a memory management error where the driver continues to reference a data structure after the memory has already been released. Because the driver fails to clear its pointer to a network packet after freeing it, it inadvertently attempts to access that invalid memory again during the next processing cycle, which can lead to system instability.

Do I need to trigger specific network traffic for this to happen?

Yes, the issue occurs during a specialized network operation where the driver prunes specific multicast frames. It does not affect generic network traffic that does not meet the criteria for this specific multicast source pruning workaround, meaning standard data transmission generally avoids this code path entirely.

Is my system at risk if it is connected to the internet?

According to Halo Surface Signal, this is highly unlikely. The vulnerability resides deep within the kernel's internal interrupt handling for a specific hardware driver, rather than in an internet-facing service or application endpoint, making it generally unreachable from the public internet.

How should I respond to CVE-2026-64113?

Your first step is to identify if your Linux infrastructure utilizes the ixgbevf driver. If confirmed, coordinate with your distribution vendor or kernel maintainers to verify if your specific kernel version includes the necessary fix, and plan to apply the updated kernel during your next scheduled maintenance cycle.

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.