CVE-2026-91827

The Ninja Forms plugin version 3.14.8 and prior for WordPress Multisite contains an incorrect authorization vulnerability that allows a subsite Administrator to trigger network-wide deletion of all Ninja Forms data. Attackers can send a crafted POST request to the admin-ajax.php endpoint with the nf_delete_all_data action and a per-site nonce to invoke migration routines that unconditionally iterate all blogs via switch_to_blog(), dropping all nf3_* tables and clearing options and transients across every subsite in the network without requiring super-admin or network-admin privileges.

The Ninja Forms plugin for WordPress versions 3.10.4 through 3.14.9 contains an unauthenticated stored cross-site scripting vulnerability in the Repeatable Fieldset feature. The parseSubmissionIndex() function accepts arbitrary strings as submission indexes without numeric validation, and admin_form_element() interpolates the index directly into HTML without escaping. An unauthenticated attacker can submit a public form with a crafted repeater child key containing malicious script payloads, which execute in an administrator's browser when viewing submissions in the WordPress admin panel.

The Ninja Forms plugin for WordPress before version 3.0.23 (when the Uploads add-on is activated) contains path traversal and unrestricted file upload vulnerabilities. This allows an attacker to traverse the file system to access files and execute code via the name and tmp_name parameters in includes/fields/upload.php.

The Ninja Forms plugin in versions up to and including 3.15.3 contains an unauthenticated Cross Site Scripting (XSS) vulnerability. An attacker can inject malicious script into the page.

Ninja Forms 3.15.3 stores an anonymous non-RTE textarea value and renders it without safe HTML encoding in the legacy submission editor. An attacker can break out of the textarea with stored script. When an Administrator opens the attacker-known direct submission URL, the script runs in the WordPress admin origin.

The Ninja Forms WordPress plugin 3.15.3 does not escape submitted form field values before outputting them on the submission edit screen in the admin area. An unauthenticated user can submit values through a public form that then execute in the browser of any high-privileged user who reviews the submission.

The Ninja Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to 3.14.6 via deserialization of untrusted input. Authenticated attackers with administrator access can inject a PHP object. No known POP chain exists, but if another plugin or theme provides one, it may allow file deletion, data theft, or code execution.

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.

The Ninja Forms WordPress plugin before version 3.15.2 does not restrict its REST abilities to administrators, treating a plugin-specific capability as equivalent to full site administration. This allows any user granted that capability to read settings and stored submissions, overwrite configuration, and create or modify arbitrary posts and pages.

The Ninja Forms WordPress plugin before 3.14.10 does not prevent user-supplied query-string input, used to pre-populate a form field's default value, from being processed as a shortcode, allowing unauthenticated attackers to execute arbitrary shortcodes registered on the site when a form so configured is embedded on a public page.