---
id: CVE-2026-98872
title: 'kernel: freevxfs: don''t BUG() on unknown typed-extent type (CVE-2026-98872)'
summary: >-
  A flaw was found in the Linux kernel's FreeVxFS filesystem driver. When
  encountering an unrecognized extent type in an on-disk structure, the driver
  triggers a fatal kernel panic instead of handling the error cleanly. A local
  user can expl…
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-617
vendor: Red Hat
product: Red Hat Enterprise Linux 6
affected:
  - enterprise_linux 6
published: '2026-10-23'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T11:01:44+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98872.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98872.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98872'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2559565'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98872'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98872'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98872.mbox
  - url: 'https://git.kernel.org/stable/c/fe40a19d571cbb584eea46038ee919d8712b2d2c'
  - url: 'https://git.kernel.org/stable/c/500e9d5bf9eff2096a21b7ac25a0a06ca46ab821'
  - url: 'https://git.kernel.org/stable/c/f1f2d54a576f0e4133b979e545abcfefd439c300'
  - url: 'https://git.kernel.org/stable/c/7ada9807e37103b41f586d34e3075e1209182b65'
  - url: 'https://git.kernel.org/stable/c/1284d687d46953fff9c0d969df108114611aca8b'
  - url: 'https://git.kernel.org/stable/c/405f13d7b270913e06e8e2b4de568985f94ef7d6'
  - url: 'https://git.kernel.org/stable/c/704d48d81dc41470e108811c32c577ada66192d4'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00213
epssPercentile: 0.11523
ingestedAt: '2026-10-23T13:24:55.584Z'
---

## Overview

A flaw was found in the Linux kernel's FreeVxFS filesystem driver. When encountering an unrecognized extent type in an on-disk structure, the driver triggers a fatal kernel panic instead of handling the error cleanly. A local user can exploit this flaw by querying file block mappings on a specially crafted filesystem, resulting in a system crash and a Denial of Service (DoS).

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98872.json)

**kernel: freevxfs: don't BUG() on unknown typed-extent type** — rated Moderate by Red Hat. Released 2026-10-23, updated 2026-10-26.

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