What is CVE-2026-4561?

CVE-2026-4561 is a medium-severity vulnerability in Dvankooten Mc4wp: Mailchimp For WordPress, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-08-22.

How severe is CVE-2026-4561?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Dvankooten Mc4wp: Mailchimp For WordPress

CVE-2026-4561

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.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

Affected products

Dvankooten Mc4wp: Mailchimp For Wordpress

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-4561?: CVE-2026-4561 is a medium-severity vulnerability in Dvankooten Mc4wp: Mailchimp For WordPress, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-08-22.
How severe is CVE-2026-4561?: Medium severity. CVSS v3 base score is 6.4 out of 10.