CVE-2026-100151
Received Received - Intake

Ninja Forms DOM-Based XSS via URL Parameter

Publication date: 2026-10-31

Last updated on: 2026-10-31

Assigner: Wordfence

Description
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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-10-31
Last Modified
2026-10-31
Generated
2026-10-31
AI Q&A
2026-10-31
EPSS Evaluated
N/A
NVD
CVE-2026-100151
EUVD
EUVD-2026-114704

Affected Vendors & Products

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability is a Reflected DOM-Based Cross-Site Scripting (XSS) flaw in the Ninja Forms WordPress plugin. It affects versions up to 3.15.5 and allows unauthenticated attackers to inject malicious scripts via URL parameters. The attack tricks users into clicking a link, which executes the injected script in their browser.

Detection Guidance

This vulnerability is specific to the Ninja Forms WordPress plugin and requires checking plugin versions. Inspect your WordPress admin panel under Plugins to see if Ninja Forms is installed and its version. If installed, verify if it is version 3.15.5 or lower.

Impact Analysis

An attacker could steal sensitive data like cookies or session tokens, redirect users to malicious sites, or perform actions on their behalf. Users clicking a crafted link may unknowingly execute harmful scripts in their browser.

Compliance Impact

This vulnerability could lead to data breaches, violating GDPR and HIPAA requirements for protecting personal and health data. Organizations may face fines or legal consequences if user data is compromised due to this flaw.

Mitigation Strategies

Update the Ninja Forms plugin to the latest version immediately. If updating is not possible, consider disabling or removing the plugin until a patch is applied. Regularly monitor WordPress plugin updates for security fixes.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-100151. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart