CVE-2026-15052
High
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.
SeverityHigh
CVSS7.2
Exploit probability—
ProductMailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder
PublishedAug 1, 2026
First seenAug 1, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| umarbajwa MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder | v ≤ 4.3.3 | — |
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