The MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Form Field Values in all versions up to, and including, 4.3.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00241.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
References
Link Providers
https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L1224 cve-icon
https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L2311 cve-icon
https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L906 cve-icon
https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L127 cve-icon
https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L179 cve-icon
https://plugins.trac.wordpress.org/changeset?reponame=&old=3627272%40mailchimp-subscribe-sm&new=3627272%40mailchimp-subscribe-sm cve-icon
https://www.wordfence.com/threat-intel/vulnerabilities/id/c3d2425e-69e5-4efe-bbc6-0ef121e74341?source=cve cve-icon
History

Sat, 01 Aug 2026 08:30:00 +0000

Type Values Removed Values Added
Description The MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Form Field Values in all versions up to, and including, 4.3.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Title MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder <= 4.3.3 - Unauthenticated Stored Cross-Site Scripting via Form Field Values
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-08-01T07:49:51.938Z

Reserved: 2026-07-08T13:23:30.631Z

Link: CVE-2026-15052

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-02T03:30:14Z