External risk intelligence

Linux Kernel RDMA Workqueue Corruption Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-45898

This vulnerability is located deep within the Linux kernel's RDMA/iWARP communication manager logic, specifically regarding internal workqueue list management. It is a kernel-level memory management issue that cannot be reached directly from the network or a public-facing service, regardless of the network-based transport protocol used.

Linux Kernel

6.11 to before 6.12.756.13 to before 6.18.146.19 to before 6.19.4

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 RDMA/iWARP component could lead to workqueue list corruption, potentially impacting system stability. This issue arises from how internal tasks are managed, and while the underlying technology is complex, its direct exposure is considered very unlikely. The main concern is confirming if this specific kernel component is in use within your environment.

Kernel bug risks system stability.
Unlikely to be externally exploitable.
Confirm usage of affected kernel component.

Attack Path

How an attacker could exploit the issue

An attacker could trigger a kernel list corruption by exploiting a flaw in how the Linux kernel's RDMA/iWARP component manages work queues. This could potentially lead to system instability or a crash, impacting the availability of the affected system.

Requires privileged access to the kernel.
Triggers when work items are processed incorrectly.
Risk of kernel crash and system instability.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in the Linux kernel's RDMA/iWARP component could lead to workqueue list corruption when specific conditions trigger repeated work submissions. This corruption occurs due to a flaw in how pending work items are managed, potentially causing system instability or unexpected behavior.

Kernel workqueue data integrity.
List corruption from repeated work submissions.
System instability or unexpected behavior.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability resides within the Linux kernel's RDMA/iwcm subsystem, impacting its workqueue management. Responsibility for addressing this issue likely falls to the infrastructure or platform teams managing the Linux kernel instances, in coordination with any application or service owners utilizing RDMA/iWARP functionality. The first practical step involves identifying all systems running vulnerable kernel versions, assessing their exposure to the network, and determining the business criticality of the affected services to prioritize remediation efforts.

Kernel and platform teams own the fix.
Verify affected Linux kernel instances.
Plan risk-based remediation activities.

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 RDMA/iwcm component in the Linux kernel?

The RDMA/iwcm component is part of the Linux kernel's networking stack. It manages iWARP (Internet Wide-area RDMA Protocol) connections, which allow computers to transfer data directly between application memories over a network. It is typically used in high-performance computing environments or data centers that require very fast, low-latency communication between servers.

What causes the issue described in CVE-2026-45898?

This is a memory management flaw involving internal data structures. Specifically, it stems from how the kernel handles a list of work tasks. When work is submitted in a certain way, the kernel can accidentally process the same task twice or reuse memory that is still being tracked, leading to a 'list corruption' error that causes the kernel to stop functioning correctly.

How is this workqueue corruption triggered?

The issue is triggered by specific, repetitive work submissions within the internal RDMA/iwcm logic. It is not triggered by standard network traffic or typical user actions. It requires the system to be actively processing RDMA work tasks in a way that exposes the flaw in the task management list. If your system is not utilizing RDMA/iWARP hardware or configurations, these code paths are not exercised.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal indicates that this risk is very unlikely. Because this flaw exists deep within internal kernel logic related to memory management, it cannot be triggered directly by an attacker sending packets over a public-facing service. Even though the CVSS score is high, the architectural location of the bug means it lacks a practical network-based path for exploitation.

What is the first step to address this CVE?

Your initial priority should be identifying which of your systems are running the affected Linux kernel versions. Check your infrastructure to see if any servers actively use RDMA/iWARP functionality. Once identified, coordinate with your platform or kernel engineering teams to plan a kernel update, as this vulnerability is resolved through standard kernel maintenance cycles.

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.