CVE-2026-8692 Overview
CVE-2026-8692 is an authorization bypass vulnerability [CWE-862] in the Vedrixa Forms – User Registration Form, Signup Form & Drag & Drop Form Builder plugin for WordPress. The flaw affects all plugin versions up to and including 1.1.1. The plugin fails to verify whether the requesting user is authorized to modify form structures before writing data to its FORMS database table. Authenticated attackers with subscriber-level access or higher can add, remove, or alter form fields by overwriting any form's structure. The required ajax-nonce value is exposed to the public frontend via wp_localize_script(), removing the only remaining barrier for low-privileged users.
Critical Impact
Subscriber-level attackers can tamper with arbitrary WordPress forms by overwriting structure data in the plugin's FORMS table.
Affected Products
- Vedrixa Forms – User Registration Form, Signup Form & Drag & Drop Form Builder plugin for WordPress
- All versions up to and including 1.1.1
- WordPress sites exposing any page that renders a Vedrixa Forms shortcode
Discovery Timeline
- 2026-05-22 - CVE-2026-8692 published to NVD
- 2026-05-22 - Last updated in NVD database
Technical Details for CVE-2026-8692
Vulnerability Analysis
The vulnerability is a missing authorization check in an AJAX handler that persists form structure data. The plugin treats nonce validation as a sufficient authorization control. Nonces in WordPress prove request origin, not user permissions. Because the plugin neither calls current_user_can() nor checks the editing user's role, any authenticated request reaching the handler is accepted. The handler then writes attacker-supplied JSON into the plugin's FORMS database table, replacing the structure of any form referenced by ID.
The impact is limited to integrity of form definitions. Attackers can change field types, remove validation, add new fields, or delete fields. Modified forms may capture data the site owner did not intend to collect, or break registration workflows. The flaw does not directly expose stored data or allow code execution.
Root Cause
The AJAX endpoint validates the ajax-nonce value but omits a capability check before persisting form data. The relevant handler logic resides in admin/class-registration-form-builder-admin.php around line 866, with related registration and frontend code in includes/class-registration-form-builder.php and public/class-registration-form-builder-public.php. The capability gap maps to [CWE-862] Missing Authorization.
Attack Vector
A subscriber-level user logs in and visits any public page containing a Vedrixa Forms shortcode. The plugin emits the ajax-nonce to the page via wp_localize_script(), so the attacker reads the nonce from the rendered HTML. The attacker then issues a POST request to the admin-ajax.php endpoint with the nonce and a target form ID, supplying attacker-controlled structure data. The handler writes the payload to the FORMS table without verifying permissions. See the Wordfence Vulnerability Report and the WordPress Plugin Code Snippet for technical details.
Detection Methods for CVE-2026-8692
Indicators of Compromise
- Unexpected modifications to records in the plugin's FORMS database table, including changed field counts or field types.
- WordPress access logs showing subscriber accounts issuing POST requests to wp-admin/admin-ajax.php with the plugin's form-save action.
- Registration or signup forms rendering fields that administrators did not configure.
Detection Strategies
- Compare current form structures against a known-good backup of the FORMS table to identify tampered rows.
- Alert on admin-ajax.php requests originating from low-privilege roles where the action parameter targets Vedrixa Forms save handlers.
- Audit recent changes to form schemas via WordPress activity log plugins or database triggers.
Monitoring Recommendations
- Forward WordPress and web server logs to a centralized log platform and create rules for anomalous AJAX activity from subscriber accounts.
- Monitor for spikes in subscriber-level POST traffic to admin-ajax.php following user registration.
- Track integrity of the plugin's database tables using file integrity and database change monitoring tools.
How to Mitigate CVE-2026-8692
Immediate Actions Required
- Update the Vedrixa Forms plugin to a patched release above version 1.1.1 as soon as the vendor publishes one.
- Restrict new user registration on affected WordPress sites until the plugin is patched.
- Review and restore any form structures that show unexpected modifications.
Patch Information
The vendor changeset is tracked in the WordPress Plugin Changeset. Administrators should upgrade to any release later than 1.1.1 and confirm the AJAX handler now performs a capability check such as current_user_can('manage_options') in addition to nonce validation.
Workarounds
- Temporarily disable the Vedrixa Forms plugin on production sites until a fixed version is installed.
- Disable open user registration in WordPress settings to prevent untrusted accounts from obtaining the ajax-nonce.
- Apply a Web Application Firewall rule blocking subscriber-level POSTs to the plugin's form-save AJAX action.
# Disable the plugin via WP-CLI until a patched release is available
wp plugin deactivate vedrixa-forms-registration-builder
# Disable open user registration
wp option update users_can_register 0
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
