---
id: CVE-2026-98865
title: >-
  kernel: sched_ext: Don't run ops.dequeue() with a DSQ lock held
  (CVE-2026-98865)
summary: >-
  A flaw was found in the Linux kernel's sched_ext subsystem. A local attacker
  could cause a Denial of Service (DoS) by triggering a deadlock condition when
  running an extensible scheduler program that accesses a dispatch queue while a
  lock …
severity: medium
cvss: 4.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-833
vendor: Red Hat
product: Linux
affected:
  - >-
    Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d <
    fe499ae9da46e297f578d4346c4c8e338c3118db
  - >-
    Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d <
    cb86607ada73185f321baa7f9d94a08a3a40bbf5
  - Linux 7.1
published: '2026-10-18'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T06:56:16+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98865'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555245'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98865'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98865'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98865.mbox
  - url: 'https://git.kernel.org/stable/c/fe499ae9da46e297f578d4346c4c8e338c3118db'
  - url: 'https://git.kernel.org/stable/c/cb86607ada73185f321baa7f9d94a08a3a40bbf5'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00169
epssPercentile: 0.06179
ingestedAt: '2026-10-18T16:47:32.460Z'
---

## Overview

A flaw was found in the Linux kernel's sched_ext subsystem. A local attacker could cause a Denial of Service (DoS) by triggering a deadlock condition when running an extensible scheduler program that accesses a dispatch queue while a lock is held during task dequeue operations. This issue causes the scheduler to hang, rendering the system unresponsive.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98865.json)

**kernel: sched_ext: Don't run ops.dequeue() with a DSQ lock held** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-24.

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.