What is CVE-2026-18328?

CVE-2026-18328 is a high-severity vulnerability in Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Builder, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-08-25.

How severe is CVE-2026-18328?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Builder

CVE-2026-18328

The Forminator Forms – Contact Form, Payment Form & Custom Form Builder plugin for WordPress is vulnerable to DOM-Based Reflected Cross-Site Scripting via the 'error_description' parameter in all versions up to, and including, 1.57.0 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. The vulnerability is only triggerable on pages hosting a Forminator form configured to use the Stripe Checkout Sessions payment API, which became the default in 1.56.0.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Builder

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-18328?: CVE-2026-18328 is a high-severity vulnerability in Wpmudev Forminator Forms – Contact Form, Payment Form & Custom Builder, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-08-25.
How severe is CVE-2026-18328?: High severity. CVSS v3 base score is 7.2 out of 10.