---
id: CVE-2026-89460
title: >-
  kernel: s390/cpum_cf: Handle CPU hotplug via prepare/dead callbacks
  (CVE-2026-89460)
summary: >-
  A flaw was found in the Linux kernel. A local user can trigger a kernel panic
  by running the `perf stat` command while CPUs are being hotplugged. This
  occurs because the system fails to properly allocate CPU event structures for
  newly onli…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-476
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T07:34:00+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89460.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89460.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89460'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532364'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89460'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89460'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89460.mbox
  - url: 'https://git.kernel.org/stable/c/337bd95507a16063687cfc286ea90de5cca48c37'
  - url: 'https://git.kernel.org/stable/c/71d46de9153e067c63a15f3b00e6364e1c0230f8'
  - url: 'https://git.kernel.org/stable/c/777d040c2f91d8d929b4a32333dfe4102b27caea'
  - url: 'https://git.kernel.org/stable/c/dcce7a06ea690d5cf46a705a9b74cf0398ac091f'
  - url: 'https://git.kernel.org/stable/c/991be92489bc7b1b6e7903debb96bd58c892dee4'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00168
epssPercentile: 0.06444
ingestedAt: '2026-09-14T15:23:07.453Z'
---

## Overview

A flaw was found in the Linux kernel. A local user can trigger a kernel panic by running the `perf stat` command while CPUs are being hotplugged. This occurs because the system fails to properly allocate CPU event structures for newly online CPUs, leading to a null pointer dereference. Successful exploitation results in a Denial of Service (DoS) due to a system crash.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89460.json)

**kernel: s390/cpum_cf: Handle CPU hotplug via prepare/dead callbacks** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

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

## Remediation

Out of support scope