---
id: CVE-2026-98866
title: >-
  kernel: sched/cache: Introduce task_struct->sched_cache_grp to fix UAF
  (CVE-2026-98866)
summary: >-
  A flaw was found in the Linux kernel. A use-after-free vulnerability, where
  memory is accessed after being released, occurs in the process scheduler cache
  component during task memory switches. A local user could exploit this flaw to
  cause…
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-825
vendor: Red Hat
product: Red Hat Enterprise Linux 6
affected:
  - enterprise_linux 6
published: '2026-10-18'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T07:31:43+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98866.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98866.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98866'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2555204'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98866'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98866'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98866.mbox
  - url: 'https://git.kernel.org/stable/c/9436130e6da72af63289a4acb3aa0c1df07a3928'
  - url: 'https://git.kernel.org/stable/c/b636fef85bda7d1bab9c0a45067ab1508d79d946'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00145
epssPercentile: 0.03753
ingestedAt: '2026-10-18T16:47:32.458Z'
---

## Overview

A flaw was found in the Linux kernel. A use-after-free vulnerability, where memory is accessed after being released, occurs in the process scheduler cache component during task memory switches. A local user could exploit this flaw to cause a Denial of Service (DoS) through a system crash.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98866.json)

**kernel: sched/cache: Introduce task_struct->sched_cache_grp to fix UAF** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-24.

Affected:

- Red Hat Enterprise Linux 6

No fix planned:

- Red Hat Enterprise Linux 6

Not affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Out of support scope