---
id: CVE-2026-89612
title: 'ntfs: reject invalid MFT LCNs from boot sector'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ntfs: reject invalid MFT LCNs from boot sector

  The NTFS boot sector stores the MFT and MFTMirr locations as unsigned
  64-bit LCNs, but parse_ntfs_boot_sector() decoded …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-787
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 11ccc9107dc460de28af90fac1f42404d9802735 <
    8f8420b68a6f05ca2b03779d8208814ec539b9e5
  - >-
    Linux >= 11ccc9107dc460de28af90fac1f42404d9802735 <
    cc9d09fef78410bcd37ac05168cbd5f6dd75d3d2
  - Linux 7.1
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:49:44.526Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89612'
references:
  - url: 'https://git.kernel.org/stable/c/8f8420b68a6f05ca2b03779d8208814ec539b9e5'
  - url: 'https://git.kernel.org/stable/c/cc9d09fef78410bcd37ac05168cbd5f6dd75d3d2'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89612.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89612'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532112'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89612'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89612'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89612.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00553
epssPercentile: 0.46015
scores:
  cna: 9.8
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.474Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

ntfs: reject invalid MFT LCNs from boot sector

The NTFS boot sector stores the MFT and MFTMirr locations as unsigned
64-bit LCNs, but parse_ntfs_boot_sector() decoded them into an s64.

A crafted high-bit value could therefore become negative and pass
the existing upper-bound check. The invalid value then propagated into
the MFT zone allocator and could result in an out-of-bounds access to
lcn_empty_bits_per_page.

## Affected

- `Linux >= 11ccc9107dc460de28af90fac1f42404d9802735 < 8f8420b68a6f05ca2b03779d8208814ec539b9e5`
- `Linux >= 11ccc9107dc460de28af90fac1f42404d9802735 < cc9d09fef78410bcd37ac05168cbd5f6dd75d3d2`
- `Linux 7.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89612.json)