---
id: CVE-2026-89520
title: >-
  kernel: sched/core: Make core-sched flips wait for in-flight selections
  (CVE-2026-89520)
summary: >-
  A flaw was found in the Linux kernel's core scheduling component. A race
  condition can occur when core scheduling flips complete during task selection,
  leading to incorrect lock handling. This can result in a resource leak and
  system insta…
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-366
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T13:04:45+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89520'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532271'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89520'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89520'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89520.mbox
  - url: 'https://git.kernel.org/stable/c/23eda24f325a6e6d686d30ec75f2e9d6745e2015'
  - url: 'https://git.kernel.org/stable/c/9d69422ddaa13526c2223444e237d948d6e44728'
  - url: 'https://git.kernel.org/stable/c/f3629c63a4af3e491381780bc6c123cb498c4c40'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00173
epssPercentile: 0.05982
scores:
  vendor: 4.7
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

A flaw was found in the Linux kernel's core scheduling component. A race condition can occur when core scheduling flips complete during task selection, leading to incorrect lock handling. This can result in a resource leak and system instability, potentially causing a denial of service.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89520.json)

**kernel: sched/core: Make core-sched flips wait for in-flight selections** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Affected:

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

No fix planned:

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

Not affected:

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

## Remediation

Fix deferred