CVE-2026-1753: 
WordPress vulnerability analysis and mitigation

CVE-2026-1753 is an authorization bypass vulnerability in the Gutena Forms WordPress plugin that allows users with Contributor-level access or above to update arbitrary boolean and array WordPress options, including sensitive settings such as users_can_register. It affects all versions of the plugin before 1.6.1 and was publicly disclosed on February 18, 2026, with the CVE record published on March 11, 2026. The vulnerability carries a CVSS v3.1 base score of 6.8 (Medium), assessed by CISA-ADP (WPScan, Feedly).

The root cause is a failure to validate which WordPress option is being updated before applying changes, classified as CWE-639 (Authorization Bypass Through User-Controlled Key) and categorized under OWASP Top 10 A5: Broken Access Control. A contributor-level user can exploit this by embedding a specially crafted shortcode or block in a post using the WordPress code editor, which triggers the plugin to update an arbitrary WordPress option without proper authorization checks. The proof-of-concept published by WPScan demonstrates setting users_can_register to 1 (enabling open user registration) via a malicious post, requiring no special server-side conditions beyond having a Contributor account (WPScan).

Successful exploitation allows a Contributor-level (or higher) authenticated attacker to manipulate critical WordPress site configuration options, including enabling open user registration (users_can_register), which could allow attackers to create new accounts and escalate privileges further. While confidentiality and availability are not directly impacted, the integrity impact is rated High due to the potential for unauthorized modification of site-wide settings that could facilitate account takeover, privilege escalation, or site defacement. The changed scope in the CVSS vector reflects that the impact extends beyond the plugin itself to the broader WordPress installation (WPScan, Feedly).

No evidence of active in-the-wild exploitation or inclusion in CISA's Known Exploited Vulnerabilities (KEV) catalog has been reported. A proof-of-concept is publicly documented by WPScan, demonstrating exploitation via a malicious post in the WordPress editor. The EPSS score is very low at approximately 0.017%, indicating a low probability of widespread exploitation in the near term (WPScan, Feedly). Exploitation requires at minimum a Contributor-level account on the target WordPress site, limiting the attack surface compared to unauthenticated vulnerabilities.

1. Obtain Contributor Access: Register or compromise a Contributor-level (or higher) account on the target WordPress site running Gutena Forms < 1.6.1.
2. Create or Edit a Post: Navigate to the WordPress post editor and switch to the code editor (block/HTML) mode.
3. Inject Malicious Block/Shortcode: Insert a crafted Gutena Forms block or shortcode that passes a target WordPress option name (e.g., users_can_register) and desired value (e.g., 1) as parameters to the plugin's option-update handler.
4. Publish or Preview the Post: Submit the post, triggering the plugin to process the block and update the specified WordPress option without authorization validation.
5. Leverage the Changed Setting: With users_can_register set to 1, register a new account (potentially with a higher role if default role is set to Administrator or Editor), or exploit other changed options to further compromise the site (WPScan).

• Logs: WordPress database logs or audit plugin logs showing unexpected updates to wp_options entries (e.g., users_can_register, array-type options) by Contributor-level users; access logs showing POST requests to WordPress AJAX or REST endpoints associated with Gutena Forms option handling.
• Database: Unexpected changes to the wp_options table, particularly users_can_register set to 1 or other boolean/array options modified outside of normal admin activity.
• User Activity: New user registrations appearing on sites that previously had registration disabled; new accounts with elevated roles created shortly after option changes.
• File System: Presence of Gutena Forms plugin version below 1.6.1 (gutena-forms directory in wp-content/plugins/) (WPScan).

Update the Gutena Forms WordPress plugin to version 1.6.1 or later, which introduces proper validation of the option being updated. Site administrators should also audit the wp_options table for unexpected changes to boolean and array options (especially users_can_register) and review recently created user accounts for unauthorized registrations. If immediate update is not possible, consider restricting Contributor-level access or temporarily deactivating the plugin (WPScan).

The vulnerability was discovered and reported by researcher Yiğit İbrahim Sağlam and submitted to WPScan, which verified and published the advisory. A brief mention appeared on Bluesky via the CVE tracking account shortly after disclosure. No significant broader media coverage or notable vendor statements beyond the WPScan advisory have been identified (WPScan).