---
id: CVE-2021-41653
title: >-
  The PING function on the TP-Link TL-WR840N EU v5 router with firmware through
  TL-WR840N(EU)_V5_171211 is vulnerable to remote code execution via a crafted
  payload in an IP address input field.
summary: >-
  The PING function on the TP-Link TL-WR840N EU v5 router with firmware through
  TL-WR840N(EU)_V5_171211 is vulnerable to remote code execution via a crafted
  payload in an IP address input field.
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'
cwe:
  - CWE-94
vendor: tp-link
product: tl-wr840n_firmware
affected:
  - tl-wr840n_firmware <= tl-wr840n\(eu\)_v5_171211
published: '2021-11-13'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-41653'
references:
  - url: 'https://k4m1ll0.com/cve-2021-41653.html'
    label: cve@mitre.org
  - url: 'https://www.tp-link.com/us/press/security-advisory/'
    label: cve@mitre.org
  - url: 'http://tp-link.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://k4m1ll0.com/cve-2021-41653.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.tp-link.com/us/press/security-advisory/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - in-the-wild
  - exploit-available
epss: 0.76045
epssPercentile: 0.99515
exploited: true
ingestedAt: '2026-07-06T01:08:17.062Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/likeww/CVE-2021-41653'
  nuclei:
    - CVE-2021-41653
  checkedAt: '2026-09-26T09:05:27.221Z'
exploitAvailable: true
---

## Overview

The PING function on the TP-Link TL-WR840N EU v5 router with firmware through TL-WR840N(EU)_V5_171211 is vulnerable to remote code execution via a crafted payload in an IP address input field.

## Affected

- `tl-wr840n_firmware <= tl-wr840n\(eu\)_v5_171211`

## Remediation

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