Stored Cross-Site Scripting Vulnerability in MailChimp Subscribe Form Plugin for WordPress
CVE-2026-15052

7.2HIGH

Key Information:

Vendor

WordPress
Status
Mailchimp Subscribe Form, Optin Builder, Popup Builder, Form Builder
Vendor
CVE Published:
1 August 2026

What is CVE-2026-15052?

The MailChimp Subscribe Form, Optin Builder, PopUp Builder, and Form Builder for WordPress are impacted by a Stored Cross-Site Scripting vulnerability. This issue arises from insufficient input sanitization and output escaping, allowing unauthenticated attackers to inject malicious scripts. When users encounter affected pages, these scripts may execute, potentially compromising user data and site integrity across all versions up to and including 4.3.3.

Affected Version(s)

MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder 0 <= 4.3.3

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.trac.wordpress.org/browser/mailchimp-subs...
https://plugins.trac.wordpress.org/browser/mailchimp-subs...

CVSS V3.1

Score:
7.2
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

she11f
.