---
id: CVE-2026-98864
title: >-
  kernel: sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task
  (CVE-2026-98864)
summary: >-
  A flaw was found in the Linux kernel's extensible scheduler (sched_ext)
  subsystem. A race condition occurs when a task is re-enqueued before a prior
  dispatch operation has completed, allowing internal scheduling states to be
  improperly ove…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-366
vendor: Red Hat
product: Linux
affected:
  - >-
    Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d <
    43457bf6550044c40bd6d3fcdf9ea66f5a55d139
  - >-
    Linux >= ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d <
    7de9a6fb44eae4f05e68c805d58b9c618815adfa
  - Linux 7.1
published: '2026-10-18'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T06:56:08+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98864.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98864.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98864'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555198'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98864'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98864'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98864.mbox
  - url: 'https://git.kernel.org/stable/c/43457bf6550044c40bd6d3fcdf9ea66f5a55d139'
  - url: 'https://git.kernel.org/stable/c/7de9a6fb44eae4f05e68c805d58b9c618815adfa'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00159
epssPercentile: 0.04971
ingestedAt: '2026-10-18T16:47:32.459Z'
---

## Overview

A flaw was found in the Linux kernel's extensible scheduler (sched_ext) subsystem. A race condition occurs when a task is re-enqueued before a prior dispatch operation has completed, allowing internal scheduling states to be improperly overwritten. A local user could trigger this flaw to cause subsequent task dispatches to be dropped, leading to stalled processes and a denial of service (DoS).

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98864.json)

**kernel: sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task** — 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.