CVE-2026-1753: Gutena Forms Auth Bypass Vulnerability

CVE-2026-1753 Overview

CVE-2026-1753 is an Authorization Bypass vulnerability affecting the Gutena Forms WordPress plugin before version 1.6.1. The plugin fails to properly validate which options can be updated, allowing authenticated users with contributor-level access and above to modify arbitrary boolean and array options within the WordPress database. This includes security-critical options such as users_can_register, which controls whether new user registrations are permitted on the site.

Critical Impact

Authenticated attackers with contributor privileges can manipulate WordPress site configuration options, potentially enabling malicious user registrations, modifying site behavior, or escalating privileges through configuration changes.

Affected Products

• Gutena Forms WordPress Plugin versions prior to 1.6.1

Discovery Timeline

• 2026-03-11 - CVE CVE-2026-1753 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-1753

Vulnerability Analysis

This vulnerability is classified under CWE-639 (Authorization Bypass Through User-Controlled Key), which occurs when an application does not properly verify that a user is authorized to access or modify a specific resource. In the context of Gutena Forms, the plugin exposes functionality that allows option updates without adequately validating which options the user should be permitted to modify.

The impact is significant because WordPress stores critical site configuration in the options table. While the vulnerability requires contributor-level authentication (limiting the attack surface to authenticated insiders or compromised accounts), the ability to modify arbitrary boolean and array options can lead to serious security consequences. An attacker could enable user registration (users_can_register), change the default user role to administrator, disable security features, or otherwise manipulate the site's configuration state.

Root Cause

The root cause lies in insufficient authorization checks within the plugin's option update functionality. The plugin does not maintain an allowlist of permitted options or properly validate that the target option is within the expected scope of the plugin's legitimate functionality. This missing validation allows authenticated users to specify arbitrary option names for modification.

Attack Vector

The vulnerability is exploitable over the network by authenticated users with at least contributor-level privileges. The attacker would need to identify the vulnerable endpoint within the Gutena Forms plugin and craft requests to update WordPress options outside the plugin's intended scope. Since the vulnerability affects boolean and array options specifically, attackers can toggle site settings or modify option arrays to alter WordPress behavior.

The attack does not require user interaction and can affect the broader WordPress installation beyond the plugin's scope, making this a cross-scope integrity violation.

Detection Methods for CVE-2026-1753

Indicators of Compromise

• Unexpected changes to WordPress options, particularly users_can_register, default_role, or other security-sensitive settings
• Suspicious option update activity originating from contributor or author user accounts
• New user registrations appearing when registration was previously disabled
• Modified plugin or theme settings that administrators did not authorize

Detection Strategies

• Monitor WordPress wp_options table for unauthorized modifications to critical settings
• Review server access logs and WordPress activity logs for unusual requests to Gutena Forms endpoints
• Implement file integrity monitoring to detect changes to WordPress configuration
• Audit user accounts with contributor-level access for suspicious activity patterns

Monitoring Recommendations

• Enable detailed logging for WordPress option changes using a security plugin
• Set up alerts for modifications to security-critical options like users_can_register and default_role
• Regularly audit user privileges and remove unnecessary contributor accounts
• Monitor for unexpected user account creations that may indicate exploitation

How to Mitigate CVE-2026-1753

Immediate Actions Required

• Update Gutena Forms WordPress plugin to version 1.6.1 or later immediately
• Audit the wp_options table for any unauthorized changes to critical settings
• Review all user accounts with contributor-level access or higher for suspicious activity
• Consider temporarily restricting contributor privileges until the patch is applied

Patch Information

The vulnerability has been addressed in Gutena Forms version 1.6.1. Site administrators should update the plugin through the WordPress admin dashboard or by downloading the latest version from the WordPress plugin repository. For detailed vulnerability information, refer to the WPScan Vulnerability Report.

Workarounds

• Temporarily deactivate the Gutena Forms plugin until the update can be applied
• Restrict or demote contributor-level user accounts that do not require elevated privileges
• Implement a Web Application Firewall (WAF) rule to block suspicious requests to the plugin's endpoints
• Enable WordPress two-factor authentication for all accounts with contributor access and above