CVE-2026-118166
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
The MC4WP: Mailchimp for WordPress plugin before version 4.15.0 does not prevent request-derived values in its dynamic content tags from being processed as shortcodes when a form is embedded with its block. This allows unauthenticated visitors to execute arbitrary registered shortcodes with attacker-chosen attributes, provided the site owner has added a request-derived tag to the form content and embedded the form with the block rather than the classic shortcode.
Risk Assessment
May lead to execution of unauthorized actions in the site context, such as disclosure of sensitive information or content modification, depending on available shortcodes.
Recommendation
Update the MC4WP: Mailchimp for WordPress plugin to version 4.15.0 or later. Avoid embedding forms with the block if not necessary until updated.
Other vulnerabilities in MC4WP: Mailchimp for WordPress
See all- CVE-2026-87917Medium
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 allows unauthenticated attackers to inject arbitrary web scripts that execute if they can trick a user into clicking a link.
- CVE-2026-4561Medium
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.
Original NVD description (English source)
The MC4WP: Mailchimp for WordPress WordPress plugin before 4.15.0 does not prevent request-derived values in its dynamic content tags from being processed as shortcodes when a form is embedded with its block, allowing unauthenticated visitors to execute arbitrary registered shortcodes with attacker-chosen attributes. This requires the site owner to have added a request-derived tag to the form content and to embed the form with the block rather than the classic shortcode.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS