CVE-2026-15052
MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder <= 4.3.3 - Unauthenticated Stored Cross-Site Scripting via Form Field Values
CVSS Score
7.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-79 |
| Vendor | umarbajwa |
| Product | mailchimp subscribe form, optin builder, popup builder, form builder |
| Published | Aug 1, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
umarbajwa / MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder
0 ≤ 4.3.3
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/c3d2425e-69e5-4efe-bbc6-0ef121e74341?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L179 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L127 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L1224 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L2311 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L906 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/changeset?reponame=&old=3627272%40mailchimp-subscribe-sm&new=3627272%40mailchimp-subscribe-sm
Credits
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