---
id: CVE-2026-89570
title: 'kernel: cxl/mce: Make the MCE notifier per-region (CVE-2026-89570)'
summary: >-
  A flaw was found in the Linux kernel's Compute Express Link (CXL) subsystem.
  Lifetime issues with the CXL Machine Check Exception (MCE) notifier can lead
  to NULL dereferences and use-after-free vulnerabilities in the MCE handler.
  This coul…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-476
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-09-11'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T06:52:21+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89570.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89570.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89570'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532510'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89570'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89570'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89570.mbox
  - url: 'https://git.kernel.org/stable/c/491d8c9ac98d55073bda778f88a5248d4cce3fa0'
  - url: 'https://git.kernel.org/stable/c/5563db13c9528a56c7161260ec75ec8690dc5608'
  - url: 'https://git.kernel.org/stable/c/775d0f4558f4cec0ee0c8966595d1add1791f36e'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00168
epssPercentile: 0.0544
scores:
  vendor: 4.1
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.474Z'
---

## Overview

A flaw was found in the Linux kernel's Compute Express Link (CXL) subsystem. Lifetime issues with the CXL Machine Check Exception (MCE) notifier can lead to NULL dereferences and use-after-free vulnerabilities in the MCE handler. This could allow an attacker to cause system instability or a denial of service.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89570.json)

**kernel: cxl/mce: Make the MCE notifier per-region** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.

Affected:

- Red Hat Enterprise Linux 10

No fix planned:

- Red Hat Enterprise Linux 10

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Affected