CVE-2026-8868: Jonathan-Robrecht Single Mailchimp

Medium severity, CVSS 6.4. EPSS: 0.3% chance of exploitation in the next 30 days.

The Single Mailchimp plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'single-mailchimp' shortcode in all versions up to, and including, 1.4. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (autocomplete, label, placeholder, btn_text, success_msg, error_msg) which are concatenated directly into HTML output by the single_mailchimp() function in shortcodes.php. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• Jonathan-Robrecht Single Mailchimp: up to and including 1.4

Published 2026-05-27. Last modified 2026-06-17.