CVE-2026-74273

Received Received - Intake

CXL Region Lock Bypass in Linux Kernel

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: cxl/region: Block region delete during region creation Expand the range lock, rename it "regions_lock", to disable region deletion in the critical period between construct_region() and attach_target(), as well as the period between device_add() and registering the remove actions. Otherwise, userspace can confuse the kernel. It can violate the assumption the region stays registered through the completion of cxl_add_to_region(). It can violate the assumption that devm_add_action_or_reset() is working with a live 'struct cxl_region'. It is ok for the region to disappear outside of those windows as that mirrors device hotplug flows where the proper locks are held.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74273

EUVD

EUVD-2026-59420

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a race condition during CXL (Compute Express Link) region creation. The issue occurs when the region lock is not properly expanded to cover critical periods between region construction and target attachment, as well as between device addition and remove action registration. This allows userspace to interfere with kernel assumptions, potentially causing confusion or instability.

Detection Guidance

This vulnerability is specific to the Linux kernel's CXL (Compute Express Link) subsystem and cannot be detected via network scanning or general system commands. It requires kernel-level inspection for race conditions during region creation and deletion. Check kernel logs for CXL-related errors or warnings using dmesg | grep cxl. Verify if the kernel version matches the patched release.

Impact Analysis

If exploited, this vulnerability could lead to system instability or crashes during CXL region operations. It may allow userspace processes to disrupt kernel operations by prematurely deleting regions or interfering with device management, potentially causing data corruption or denial of service.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It involves a race condition in the Linux kernel's CXL region management, which could lead to kernel confusion but does not inherently impact data protection or privacy requirements.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for CVE-2026-74273. If immediate patching is not possible, restrict access to CXL device operations via kernel module parameters or disable CXL functionality if unused. Monitor kernel logs for suspicious activity related to region creation/deletion.

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