MC4WP Mailchimp Plugin up to 4.14.x on WordPress Dynamic Content Tag injection

Summaryinfo

A vulnerability has been found in MC4WP Mailchimp Plugin up to 4.14.x and classified as critical. This affects an unknown part of the component Dynamic Content Tag. Performing a manipulation results in injection. This vulnerability was named CVE-2026-118166. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in MC4WP Mailchimp Plugin up to 4.14.x. It has been classified as critical. This affects an unknown part of the component Dynamic Content Tag. The manipulation with an unknown input leads to a injection vulnerability. CWE is classifying the issue as CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at wpscan.com. This vulnerability is uniquely identified as CVE-2026-118166 since 10/27/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

Upgrading to version 4.15.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-117972). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Name

• MC4WP Mailchimp Plugin

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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