---
id: CVE-2021-3501
title: A flaw was found in the Linux kernel in versions before 5.12
summary: >-
  A flaw was found in the Linux kernel in versions before 5.12. The value of
  internal.ndata, in the KVM API, is mapped to an array index, which can be
  updated by a user process at anytime which could lead to an out-of-bounds
  write. The hig…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H'
cwe:
  - CWE-787
vendor: redhat
product: virtualization
affected:
  - linux_kernel < 5.12
  - enterprise_linux = 8.0
  - enterprise_linux_for_real_time = 8
  - enterprise_linux_for_real_time_for_nfv = 8
  - enterprise_linux_for_real_time_for_nfv_tus = 8.4
  - enterprise_linux_for_real_time_tus = 8.4
  - fedora = 33
  - virtualization = 4.0
  - virtualization_host = 4.0
  - cloud_backup
  - solidfire_baseboard_management_controller_firmware
  - h300s_firmware
  - h500s_firmware
  - h700s_firmware
  - h300e_firmware
  - h500e_firmware
  - h700e_firmware
  - h410s_firmware
  - h410c_firmware
patched:
  - linux_kernel 5.12
published: '2021-05-06'
updated: '2026-08-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3501'
references:
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1950136'
    label: secalert@redhat.com
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20210618-0008/'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1950136'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210618-0008/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00374
epssPercentile: 0.31332
ingestedAt: '2026-08-05T22:52:53.164Z'
---

## Overview

A flaw was found in the Linux kernel in versions before 5.12. The value of internal.ndata, in the KVM API, is mapped to an array index, which can be updated by a user process at anytime which could lead to an out-of-bounds write. The highest threat from this vulnerability is to data integrity and system availability.

## Affected

- `linux_kernel < 5.12`
- `enterprise_linux = 8.0`
- `enterprise_linux_for_real_time = 8`
- `enterprise_linux_for_real_time_for_nfv = 8`
- `enterprise_linux_for_real_time_for_nfv_tus = 8.4`
- `enterprise_linux_for_real_time_tus = 8.4`
- `fedora = 33`
- `virtualization = 4.0`
- `virtualization_host = 4.0`
- `cloud_backup`
- `solidfire_baseboard_management_controller_firmware`
- `h300s_firmware`
- `h500s_firmware`
- `h700s_firmware`
- `h300e_firmware`
- `h500e_firmware`
- `h700e_firmware`
- `h410s_firmware`
- `h410c_firmware`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.12`