Vulnerability details
CVE-2026-15052
umarbajwa MailChimp Subscribe Form
MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder <= 4.3.3 - Unauthenticated Stored Cross-Site Scripting via Form Field Values
CVSS 3.1
7.2High
Official 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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.2High | 3.1 | CVEProject cvelistV5 (CNA) (Wordfence) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| umarbajwa | MailChimp Subscribe Form, Optin Builder, PopUp Builder, Form Builder | v ≤ 4.3.3 | CVEProject cvelistV5 (CNA) |
References and advisories
7- https://www.wordfence.com/threat-intel/vulnerabilities/id/c3d2425e-69e5-4efe-bbc6-0ef121e74341?source=cve
- https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L179
- https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/integrations/form-builder-database/extension.php#L127
- https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L1224
- https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L2311
- https://plugins.trac.wordpress.org/browser/mailchimp-subscribe-sm/tags/4.3.3/admin/classes/ajax-requests-class.php#L906
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3627272%40mailchimp-subscribe-sm&new=3627272%40mailchimp-subscribe-sm
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Details
- Published
- 2026-08-01
- Last updated
- 2026-08-03
- State
- Published
- Assigner (CNA)
- Wordfence
Exploit prediction (EPSS)
0.41%
Probability of exploitation in 30 days
36.4%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')