---
id: CVE-2026-89517
title: >-
  kernel: sched_ext: Fix rq->core_pick corruption under core scheduling
  (CVE-2026-89517)
summary: >-
  A flaw was found in the Linux kernel's `sched_ext` component, which handles
  core scheduling. When multiple selections on the same core interleave due to a
  dropped lock, they can corrupt the scheduling state. This corruption can lead
  to a N…
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 OpenShift Container Platform 4
affected:
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T12:58:35+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89517'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532211'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89517'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89517'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89517.mbox
  - url: 'https://git.kernel.org/stable/c/cdafb68155bee2d5c4e50c12e4606323e9334e6b'
  - url: 'https://git.kernel.org/stable/c/d954004205c1a1d3f59ce8482b559266c15600fa'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00198
epssPercentile: 0.09806
ingestedAt: '2026-09-14T11:11:19.887Z'
---

## Overview

A flaw was found in the Linux kernel's `sched_ext` component, which handles core scheduling. When multiple selections on the same core interleave due to a dropped lock, they can corrupt the scheduling state. This corruption can lead to a NULL dereference, tasks remaining active after being dequeued, system deadlocks, and ultimately cause the kernel to crash, resulting in a Denial of Service (DoS).

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89517.json)

**kernel: sched_ext: Fix rq->core_pick corruption under core scheduling** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Not affected:

- Red Hat Enterprise Linux 10
- 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

Refer to the advisory for fix availability.