CVE-2026-18328

Forminator Forms <= 1.57.0 - Unauthenticated DOM-Based Cross-Site Scripting via 'error_description' Parameter

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.

We have discovered 74,388 live websites that are affected by CVE-2026-18328.

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Affected Software

Product  Forminator
Category Wordpress Plugins
Vulnerable Domains74,388 live websites (100% of Forminator install base)
Vulnerable Versions
  • from 0 through 1.57
Vulnerable Versions Count156 versions ( 100% of all versions)


Common Weakness Enumeration

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')



Details

  • Published - Aug 25, 2026
  • Updated - Aug 25, 2026

Credits

  • Adrien Brunner (finder)

Website Distribution by Country

Number of websites using CVE-2026-18328
United States23,616 websites


Germany6,174 websites
GB5,226 websites
France5,225 websites
Denmark3,539 websites
Netherlands2,320 websites
Canada2,308 websites
Italy2,183 websites
India2,029 websites
Australia1,884 websites

Website Distribution by TLD

Number of websites using CVE-2026-18328
.com31,230 websites
.org3,967 websites
.de3,654 websites
.co.uk3,275 websites
.dk3,067 websites
.fr2,822 websites
.nl2,113 websites
.com.au1,739 websites
.it1,594 websites
.net1,322 websites

Vulnerable Versions

Vulnerable versions are highlighted in red

Websites affected by CVE-2026-18328

Top websites that are affected by CVE-2026-18328. Please click on the "Contact us" link to get more information.
DomainCountryRankContacts
********.com United States*,***
********.org United States*,***
***********.dk Denmark*,***
************.org France*,***
*******.com United States*,***
***********.net United States**,***
**************.com United States**,***
********.it Italy**,***
*********.gr Greece**,***
*******.com GB**,***
See full domain list

FAQ

CVE-2026-18328 is Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Forminator
A total of 74,388 websites have been identified as vulnerable to CVE-2026-18328, based on global website indexing conducted by WebTechSurvey.
The Forminator is affected by the CVE-2026-18328 vulnerability.
Forminator versions up to and including 1.57 are vulnerable to CVE-2026-18328.