---
id: CVE-2026-89745
title: 'kernel: debugfs: Fix lockdown check for mmap_prepare (CVE-2026-89745)'
summary: >-
  A flaw was found in the Linux kernel's debugfs component. The lockdown
  mechanism, designed to enhance system integrity, did not properly account for
  files using the `mmap_prepare` operation. This oversight could allow an
  attacker to bypass…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-414
vendor: Red Hat
product: Red Hat Enterprise Linux 6
affected:
  - enterprise_linux 6
published: '2026-09-11'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T08:20:44+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89745.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89745.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89745'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532369'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89745'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89745'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89745.mbox
  - url: 'https://git.kernel.org/stable/c/e7f6a6b5741d16fdac7adaecbe0fa52ae756f208'
  - url: 'https://git.kernel.org/stable/c/f81808de37338aac8e167f99bfae647b1b835c70'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00198
epssPercentile: 0.08435
ingestedAt: '2026-09-14T11:11:19.884Z'
---

## Overview

A flaw was found in the Linux kernel's debugfs component. The lockdown mechanism, designed to enhance system integrity, did not properly account for files using the `mmap_prepare` operation. This oversight could allow an attacker to bypass kernel lockdown restrictions when the system is operating in integrity mode, potentially compromising system integrity.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89745.json)

**kernel: debugfs: Fix lockdown check for mmap_prepare** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-16.

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