Auth bypass in Dvankooten Mc4wp: Mailchimp For Wordpress
CVE-2026-1781
The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 4.11.1. This is due to the plugin trusting the `_mc4wp_action` POST parameter without validation, allowing…
Vulnerability class: Broken Access Control
EPSS: 0.001 (22.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.
Affected products
- Dvankooten Mc4wp: Mailchimp For Wordpress — versions 0
Weakness classification (CWE)
References
- www.wordfence.com/threat-intel/vulnerabilities/id/10262aa9-5656-4a2b-aeb5-06001…
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/…
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/…
- plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/…
- cwe.mitre.org/data/definitions/862.html
- github.com/ibericode/mailchimp-for-wordpress/commit/5fdebc2a5e22d11287d011697a6…
- plugins.trac.wordpress.org/changeset
Frequently asked questions
- What is CVE-2026-1781?
- CVE-2026-1781 is a medium-severity vulnerability in Dvankooten Mc4wp: Mailchimp For Wordpress, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-03-11.
- How severe is CVE-2026-1781?
- Medium severity. CVSS v3 base score is 6.5 out of 10.