Forminator Forms <= 1.57.0 - Unauthenticated DOM-Based Cross-Site Scripting via 'error_description' Parameter
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18328
- 2026-10-03 Alias added: GHSA-5mm9-h6w4-7v8m
References
Other 7
- 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
More wpmudev vulnerabilities
- TI-2023-04240 Forminator <= 1.24.6 - Unauthenticated Arbitrary File Upload CVSS 3.1CRITICAL 9.8
- TI-2023-04683 Defender Security < 4.1.0 - Protection Bypass (Hidden Login Page) CVSS 3.1MEDIUM 5.3
- TI-2026-13248 Forminator Forms <= 1.56.1 - Unauthenticated Arbitrary File Upload via Forged Upload Field Configuration CVSS 3.1CRITICAL 9.8
- TI-2025-05864 Forminator Forms – Contact Form, Payment Form & Custom Form Builder <= 1.44.2… CVSS 3.1HIGH 8.8
- TI-2024-20466 SQL injection in wpmudev Forminator CVSS 3.1HIGH 7.2
- TI-2024-07873 Hustle < 7.8.5 - Admin+ Stored XSS CVSS 3.1MEDIUM 4.8
Sources
- CVE-2026-18328 · CVE Program
- CVE-2026-18328 · NVD
- FIRST EPSS
- GHSA-5mm9-h6w4-7v8m · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences