---
id: CVE-2021-34866
title: >-
  This vulnerability allows local attackers to escalate privileges on affected
  installations of Linux Kernel 5.14-rc3
summary: >-
  This vulnerability allows local attackers to escalate privileges on affected
  installations of Linux Kernel 5.14-rc3. An attacker must first obtain the
  ability to execute low-privileged code on the target system in order to
  exploit this v…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-843
  - CWE-843
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.8, < 5.10.62'
  - 'linux_kernel >= 5.11, < 5.13.14'
  - h410c_firmware
  - h300s_firmware
  - h500s_firmware
  - h700s_firmware
  - h300e_firmware
  - h500e_firmware
  - h700e_firmware
  - h410s_firmware
patched:
  - linux_kernel 5.13.14
published: '2022-01-25'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:17:36.293'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-34866'
references:
  - url: 'https://security.netapp.com/advisory/ntap-20220217-0008/'
    label: zdi-disclosures@trendmicro.com
  - url: 'https://www.zerodayinitiative.com/advisories/ZDI-21-1148/'
    label: zdi-disclosures@trendmicro.com
  - url: 'https://security.netapp.com/advisory/ntap-20220217-0008/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.zerodayinitiative.com/advisories/ZDI-21-1148/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00972
epssPercentile: 0.60812
zeroDay: true
ingestedAt: '2026-10-08T22:11:53.744Z'
---

## Overview

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.14-rc3. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs, which can result in a type confusion condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-14689.

## Affected

- `linux_kernel >= 5.8, < 5.10.62`
- `linux_kernel >= 5.11, < 5.13.14`
- `h410c_firmware`
- `h300s_firmware`
- `h500s_firmware`
- `h700s_firmware`
- `h300e_firmware`
- `h500e_firmware`
- `h700e_firmware`
- `h410s_firmware`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.13.14`