---
id: CVE-2026-31447
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: reject mount if bigalloc with s_first_data_block != 0

  bigalloc with s_first_data_block != 0 is not supported, reject mounting
  it.
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: reject mount if bigalloc with s_first_data_block != 0

  bigalloc with s_first_data_block != 0 is not supported, reject mounting
  it.
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.2, < 5.10.253'
  - 'linux_kernel >= 5.11, < 5.15.203'
  - 'linux_kernel >= 5.16, < 6.1.168'
  - 'linux_kernel >= 6.2, < 6.6.131'
  - 'linux_kernel >= 6.7, < 6.12.80'
  - 'linux_kernel >= 6.13, < 6.18.21'
  - 'linux_kernel >= 6.19, < 6.19.11'
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.11
published: '2026-04-22'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:19:05.970'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31447'
references:
  - url: 'https://git.kernel.org/stable/c/3822743dc20386d9897e999dbb990befa3a5b3f8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3a926957cc95899ef88529710836edadc03c71a1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5ad6d994255e27a3254079dfb50ca861fc31f2d0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7b58c110b4e1f028eb38eec9ed3555e9be81c8b0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7d5b04290156c3fc316eecc86a4f9d201ab7d44a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ad1f6d608f33f59d21a3d025615d6786a6443998'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b77de3fceafbb39f30e4ff5dc986f863d5456417'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d787d3ae96648dc14a3b7ca8fde817177e82c1c7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-457936.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00143
epssPercentile: 0.03578
ingestedAt: '2026-09-08T15:33:26.990Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:09:23.320699Z'
---

## Overview

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

ext4: reject mount if bigalloc with s_first_data_block != 0

bigalloc with s_first_data_block != 0 is not supported, reject mounting
it.

## Affected

- `linux_kernel >= 3.2, < 5.10.253`
- `linux_kernel >= 5.11, < 5.15.203`
- `linux_kernel >= 5.16, < 6.1.168`
- `linux_kernel >= 6.2, < 6.6.131`
- `linux_kernel >= 6.7, < 6.12.80`
- `linux_kernel >= 6.13, < 6.18.21`
- `linux_kernel >= 6.19, < 6.19.11`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.11`