CVE-2026-4561
MC4WP: Mailchimp for WordPress <= 4.12.0 - Authenticated (Author+) Stored Cross-Site Scripting via Form Response Messages
CVSS Score
6.4
EPSS Score
0.0%
EPSS Percentile
0th
The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the form response message post meta fields (e.g., 'text_subscribed', 'text_error') in all versions up to, and including, 4.12.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
| CWE | CWE-79 |
| Vendor | dvankooten |
| Product | mc4wp: mailchimp for wordpress |
| Published | Aug 22, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
dvankooten / MC4WP: Mailchimp for WordPress
0 ≤ 4.12.0
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/641b739d-f888-4327-b1c5-c95de39ee011?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form.php#L295 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form-element.php#L116 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/trunk/includes/forms/class-form-manager.php#L104 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/changeset/3491781/
Credits
Osvaldo Noe Gonzalez Del Rio (Os)