CVE-2026-105973 in Visual Form Builder Plugin
Summary
by MITRE • 10/16/2026
The Visual Form Builder WordPress plugin through 3.1 does not perform authorization or nonce checks when reordering form fields, allowing any authenticated user (Subscriber and above) to alter the field structure of any form on the site, persistently breaking its public rendering.
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Analysis
by VulDB Data Team • 10/16/2026
The vulnerability identified in the Visual Form Builder WordPress plugin prior to version 3.1 represents a critical failure in access control mechanisms, specifically categorized under CWE-862 Missing Authorization and CWE-352 Cross-Site Request Forgery due to the absence of nonce verification. This flaw allows any authenticated user with at least Subscriber-level privileges to manipulate the internal structure of form fields without proper validation or permission checks. In typical WordPress environments, even low-privilege users such as subscribers are granted certain capabilities for content interaction but should not have administrative control over plugin configurations or structural elements that affect site functionality. The lack of authorization checks means that the application fails to verify whether the requesting user has the requisite permissions to perform the action of reordering form fields, thereby violating the principle of least privilege and enabling unauthorized state changes within the application logic.
From a technical perspective, the operational impact stems directly from the missing nonce check during the AJAX request responsible for field reordering. Nonces in WordPress serve as one-time use tokens designed to prevent Cross-Site Request Forgery attacks by ensuring that requests originate from legitimate sources authorized by the current session. Without this safeguard, an attacker can craft malicious URLs or scripts that trigger the reorder functionality on behalf of any logged-in user whose browser holds a valid session cookie for the targeted WordPress site. This capability allows the persistence of altered field structures across page loads and server restarts because the changes are typically saved to the database immediately upon execution. Consequently, this leads to persistent denial-of-service conditions where public-facing forms become broken or unusable due to misaligned fields, missing labels, or incorrect data mapping configurations that result from unauthorized structural modifications.
The security implications extend beyond simple functional disruption, as this vulnerability can be leveraged for more sophisticated attacks depending on the specific implementation of the form builder and its integration with other plugins. For instance, if the reordered fields influence how user input is processed or stored, an attacker might attempt to inject malicious payloads into subsequent data entry points by manipulating field order in ways that bypass intended validation logic. Furthermore, this vulnerability aligns with MITRE ATT&CK technique T1498 Network Denial of Service, as it enables attackers to degrade the availability and integrity of web applications through unauthorized configuration changes. It also relates to T1078 Valid Accounts, since exploitation requires valid authentication credentials, highlighting the risk posed by compromised or shared low-privilege accounts within an organization's digital infrastructure.
Mitigation strategies must prioritize immediate patching to version 3.2 or later where these authorization and nonce checks have been implemented correctly. In environments where updating is not immediately feasible, administrators should restrict user roles that possess access to the Visual Form Builder interface, ensuring that only users with Administrator privileges can interact with form configuration features. Additionally, implementing strict Content Security Policy headers and monitoring for unusual AJAX activity patterns related to form field manipulation can provide supplementary layers of defense against exploitation attempts. Regular security audits focusing on input validation and authorization checks across all plugin endpoints are essential to prevent similar vulnerabilities from being introduced in future updates or within other third-party extensions that handle sensitive state changes without adequate verification mechanisms.