---
id: CVE-2026-100151
title: >-
  Ninja Forms <= 3.15.5 - Reflected DOM-Based Cross-Site Scripting via
  'querystring:<key>' URL Parameter
summary: >-
  The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures &
  AI Form Builder plugin for WordPress is vulnerable to Reflected DOM-Based
  Cross-Site Scripting via 'querystring:<key>' URL Parameter in all versions up
  to, an…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
vendor: kstover
product: >-
  Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI
  Form Builder
affected:
  - >-
    ninja_forms_contact_form_builder_with_calculators_quizzes_signatures_ai_form_builder
    <= 3.15.5
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-01T17:33:54.649429Z'
published: '2026-10-31'
updated: '2026-11-01'
sourceUpdated: '2026-11-01T17:34:18.422Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-100151'
references:
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/82ace2e3-1120-4be9-a7c6-b64590c8a35f?source=cve
  - url: >-
      https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/assets/js/min/front-end.js
  - url: >-
      https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Templates/fields-html.html#L2
  - url: >-
      https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/MergeTags/Other.php#L41
  - url: 'https://wordpress.org/plugins/ninja-forms/'
  - url: >-
      https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/assets/js/min/front-end.js
tags:
  - cve.org
epss: 0.00231
epssPercentile: 0.14048
ingestedAt: '2026-11-05T18:28:50.808Z'
---

## Overview

The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to Reflected DOM-Based Cross-Site Scripting via 'querystring:<key>' URL Parameter in all versions up to, and including, 3.15.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. This bypass is triggered when an attacker supplies a matching field:&lt;key&gt; URL parameter that causes the server to fully resolve the {field:*} placeholder, forcing the client-side else-branch to abandon the server-sanitized value and reconstruct field content from the raw query string.

## Affected

- `ninja_forms_contact_form_builder_with_calculators_quizzes_signatures_ai_form_builder <= 3.15.5`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.