---
id: CVE-2026-87917
title: >-
  The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to
  Reflected Cross-Site Scripting via 'data' Dynamic Content Tag in all versions
  up to, and including, 4.14.0 due to insufficient input sanitization and output
  escapin…
summary: >-
  The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to
  Reflected Cross-Site Scripting via 'data' Dynamic Content Tag in all versions
  up to, and including, 4.14.0 due to insufficient input sanitization and output
  escapin…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: dvankooten
product: 'MC4WP: Mailchimp for WordPress'
affected:
  - mc4wp_mailchimp_for_wordpress <= 4.14.0
published: '2026-09-19'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T13:33:33.387'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-87917'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/class-dynamic-content-tags.php#L127
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/forms/class-form-tags.php#L109
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/forms/class-form-tags.php#L57
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&new=3689679%40mailchimp-for-wp%2Ftags%2F4.14.1&old=3655905%40mailchimp-for-wp%2Ftags%2F4.14.0
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&new=3698084%40mailchimp-for-wp%2Ftags%2F4.14.1&old=3655905%40mailchimp-for-wp%2Ftags%2F4.14.0
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/ee4f837a-d0b5-48df-8c96-2a294985612e?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - cve.org
epss: 0.0038
epssPercentile: 0.29241
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-19T13:25:27.729206Z'
ingestedAt: '2026-09-19T07:59:56.105Z'
---

## Overview

The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via 'data' Dynamic Content Tag in all versions up to, and including, 4.14.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

## Remediation

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