CVE-2026-19769: Ninja Forms <= 3.15.1 - Unauthenticated Stored Cross-Site Scripting via Repeater Child 'type' Confusion via Unmatched Array Key
The Ninja Forms – The Contact Form Builder That Grows With You plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Repeater Child 'type' Confusion via Unmatched Array Key in all versions up to, and including, 3.15.1 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. Exploitation requires the Ninja Forms File Uploads add-on to be active, as the attack routes the unwhitelisted child entry through the File Uploads handler to write an attacker-supplied HTML file containing arbitrary JavaScript into any web-server-writable directory, including the site root, where it is served from the site's own origin.
Affected Software
Event History
Frequently Asked Questions
Which sites are exposed to exploitation?
Sites running Ninja Forms version 3.15.1 or earlier are affected when the Ninja Forms File Uploads add-on is active. The issue can write an attacker-supplied HTML file into any directory writable by the web server, including the site root.
Does exploitation require an authenticated WordPress account or user interaction?
No. The vulnerability is exploitable by an unauthenticated attacker, and no user interaction is required for injection. The stored script executes when someone later accesses the injected page.
What capability does a successful attacker gain?
An attacker can cause arbitrary JavaScript to be served from the affected site's own origin. This can lead to script execution in the browsers of users who visit the injected page.
What configuration detail is most important to check during triage?
Verify whether the Ninja Forms File Uploads add-on is active. The described exploitation path depends on that add-on's handler to write the attacker-controlled HTML file.