MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder vulnerabilities
Plugin slug mailchimp-subscribe-sm · 7 known vulnerabilities · latest disclosed 2026-08-11 · WordPress.org page
Every listed vulnerability has a fix. Version 4.3.4 or later is not affected by any of them. If your site runs an older version, update it.
3 of 7 rated high or critical (CVSS 7 or more).
Known vulnerabilities in MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder
| Severity | Affected versions | Fixed in | CVE | Published | Details |
|---|---|---|---|---|---|
| High 7.2 | <= 4.3.3 | 4.3.4 | CVE-2026-27536 | 2026-08-11 | Advisory |
| High 7.2 | <= 4.3.3 | 4.3.4 | CVE-2026-15052 | 2026-07-31 | Advisory |
| Medium 6.4 | <= 4.1 | 4.2 | CVE-2025-22727 | 2025-01-15 | Advisory |
| Medium 4.4 | <= 4.0.9.7 | 4.0.9.8 | CVE-2024-43211 | 2024-08-09 | Advisory |
| Medium 4.4 | <= 4.0.9.1 | 4.0.9.2 | CVE-2023-33328 | 2023-05-22 | Advisory |
| Medium 6.1 | <= 4.0.9.3 | 4.0.9.4 | CVE-2023-32517 | 2023-05-10 | Advisory |
| High 8.8 | < 1.2 | 1.2 | none | 2015-04-21 | Advisory |
Check if a site is affected
Enter a site address to see which version of MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder and other plugins it runs, and whether they match a known vulnerability.
Questions
Is the MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder plugin safe to use?
All 7 known issues are fixed in current versions (4.3.4 or later). Keeping it updated is what matters.
How do I check which version of MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder my site runs?
In WordPress go to Plugins > Installed Plugins. From the outside, the free PluginPeek scan below reads the version from the site's public files.
How do I fix a vulnerable plugin?
Make a full backup, then update it from Dashboard > Updates and check the site afterwards. If you would rather not, we can do it for a fixed $99, paid after you have checked the site.