---
id: CVE-2026-89521
title: 'kernel: sched/core: Handle pick_task() releasing the rq lock (CVE-2026-89521)'
summary: >-
  A flaw was found in the Linux kernel's core scheduling component. This issue
  occurs when the `pick_task()` function releases the run queue (rq) lock,
  allowing an interleaving selection to invalidate the scheduler's internal
  state. This inc…
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-367
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T21:34:35+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89521.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89521.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89521'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532178'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89521'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89521'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89521.mbox
  - url: 'https://git.kernel.org/stable/c/88ed5a66467ca2a5148b9997af9c71d8c43060ad'
  - url: 'https://git.kernel.org/stable/c/c10b216a072ff5c57bc880a05f87eb519aecc529'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00153
epssPercentile: 0.03686
scores:
  vendor: 5.5
  cna: 7.3
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

A flaw was found in the Linux kernel's core scheduling component. This issue occurs when the `pick_task()` function releases the run queue (rq) lock, allowing an interleaving selection to invalidate the scheduler's internal state. This inconsistency can lead to incorrect task selection and skewed resource accounting, potentially affecting system stability or causing 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 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89521.json)

**kernel: sched/core: Handle pick_task() releasing the rq lock** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

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

Fix deferred