CVE-2026-19220 Overview
CVE-2026-19220 affects the Forminator Forms WordPress plugin in versions prior to 1.57.1. The plugin fails to verify whether site registration is enabled on a WordPress multisite network before creating a site signup. Unauthenticated visitors can exploit this flaw to create new sites on a multisite network and obtain administrator privileges on those sites. The issue is classified under [CWE-269] Improper Privilege Management. Successful exploitation grants attackers control over newly registered subsites within the network, providing a foothold for further abuse such as content injection or plugin-level tampering.
Critical Impact
Unauthenticated attackers can create sites on WordPress multisite networks and gain administrator privileges even when site registration is disabled.
Affected Products
- Forminator Forms WordPress plugin versions before 1.57.1
- WordPress multisite installations running the vulnerable plugin
- Networks where site registration is expected to be disabled
Discovery Timeline
- 2026-08-26 - CVE-2026-19220 published to NVD
- 2026-08-26 - Last updated in NVD database
Technical Details for CVE-2026-19220
Vulnerability Analysis
The Forminator Forms plugin exposes a site signup workflow tied to WordPress multisite functionality. The plugin routes user-submitted form data into the multisite signup logic without first checking the network configuration. In a correctly configured network, administrators can disable open registration to prevent arbitrary site creation. The plugin bypasses that setting entirely.
An unauthenticated visitor submitting a crafted form request can trigger the signup path. The plugin then provisions a new site and assigns the requesting user administrator rights on that site. The requester gains a controllable subsite hosted within the target network.
Root Cause
The root cause is missing enforcement of the multisite users_can_register and network-level signup settings before invoking site creation. The plugin trusts the form submission path rather than deferring to WordPress core registration policy. This is a business logic and privilege management flaw rather than a memory safety issue.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker identifies a WordPress multisite installation running Forminator Forms below version 1.57.1. The attacker submits a signup request through a plugin-exposed endpoint. The plugin creates the site and elevates the attacker to administrator on the new subsite. Attack complexity is elevated because the target must be a multisite deployment with the plugin present and configured to expose the vulnerable form.
No verified proof-of-concept code has been published. See the WPScan Vulnerability Report for technical references.
Detection Methods for CVE-2026-19220
Indicators of Compromise
- Unexpected new sites appearing in the WordPress multisite Network Admin site list
- New administrator accounts on freshly created subsites tied to unknown email addresses
- Signup events in wp_signups and wp_blogs tables originating from anonymous form submissions
Detection Strategies
- Audit the wp_signups and wp_blogs tables for entries created while network registration was configured as disabled
- Correlate web server access logs for POST requests to Forminator form endpoints preceding new site creation events
- Review WordPress activity logs for wpmu_new_blog and wpmu_new_user hooks fired without an authenticated administrator context
Monitoring Recommendations
- Enable file integrity monitoring across wp-content/plugins/forminator/ to detect tampering
- Forward WordPress and web server logs to a centralized log platform for cross-network correlation
- Alert on any change in the count of registered subsites when the network signup policy is set to disabled
How to Mitigate CVE-2026-19220
Immediate Actions Required
- Update the Forminator Forms plugin to version 1.57.1 or later on every site in the network
- Audit all subsites created since the plugin was installed and remove unauthorized sites and administrator accounts
- Confirm the multisite network signup configuration matches the intended policy after patching
Patch Information
Upgrade Forminator Forms to version 1.57.1 or later. This release enforces the network site registration setting before creating a signup. Refer to the WPScan Vulnerability Report for the fix reference.
Workarounds
- Disable the Forminator Forms plugin network-wide until the patched version can be deployed
- Remove or restrict access to any Forminator forms that expose the site signup workflow
- Place the multisite network behind an authenticated reverse proxy or IP allowlist during the remediation window
# Verify installed Forminator version and update via WP-CLI
wp plugin get forminator --field=version --allow-root
wp plugin update forminator --version=1.57.1 --allow-root
wp plugin deactivate forminator --network --allow-root
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
