CVE-2026-87917: MC4WP: Mailchimp for WordPress · Cross-site Scripting
Affects MC4WP: Mailchimp for WordPressSource CVE Database V5
Not known to be exploited · CVSS 6.1 Medium.
Data as of 2 Nov 2026, 22:58 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 19 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| dvankootenMC4WP: Mailchimp for WordPress | Affected
| Fixed in– |
AI-suggested
Until a fix is applied, users should consider disabling or restricting use of the 'data' Dynamic Content Tag or applying web application firewall rules to block malicious input patterns.
Description
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.
References
- wordfence.com/threat-intel/vulnerabilities/id/ee4f837a-d0b5-48df-8c96-2a294985612e?source=cve (opens in a new tab)
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/class-dynamic-content-tags.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/forms/class-form-tags.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.14.0/includes/forms/class-form-tags.php (opens in a new tab)
- plugins.trac.wordpress.org/changeset?reponame=&new=3689679%40mailchimp-for-wp%2Ftags%2F4.14.1&old=3655905%40mailchimp-for-wp%2Ftags%2F4.14.0 (opens in a new tab)
- plugins.trac.wordpress.org/changeset?reponame=&new=3698084%40mailchimp-for-wp%2Ftags%2F4.14.1&old=3655905%40mailchimp-for-wp%2Ftags%2F4.14.0 (opens in a new tab)