CVE-2025-13029 is a critical security vulnerability identified in the Knowband Mobile App Builder WordPress plugin, specifically in versions prior to 3.0.0. The vulnerability is classified under CWE-862 (Missing Authorization), indicating that the plugin's REST API endpoint responsible for deleting users does not enforce proper authorization checks. Consequently, unauthenticated attackers can send crafted HTTP requests to this endpoint to delete arbitrary users from the WordPress site. This lack of authorization bypass means that any external attacker, without needing valid credentials or user interaction, can disrupt the user base of the affected site. The impact is particularly severe because user deletion can remove administrators or other privileged accounts, potentially locking out legitimate users and disrupting site operations. The plugin is commonly used to build mobile apps integrated with WordPress e-commerce stores, so the affected systems often handle sensitive customer and business data. Although no public exploits have been reported yet, the vulnerability's nature and ease of exploitation make it a high-risk issue. The absence of a CVSS score means severity must be assessed based on the vulnerability's characteristics: it affects confidentiality and availability by enabling unauthorized user deletions, requires no authentication, and affects potentially many WordPress sites using the plugin. The vulnerability was reserved in November 2025 and published at the end of December 2025, with no patch currently available, emphasizing the urgency for organizations to implement interim mitigations.

For European organizations, this vulnerability can lead to significant operational disruptions, especially for e-commerce and service providers relying on WordPress and the Knowband Mobile App Builder plugin. Unauthorized deletion of users can result in loss of administrative access, denial of service, and potential data integrity issues if user roles and permissions are manipulated. This can affect customer trust, lead to financial losses, and complicate compliance with data protection regulations such as GDPR due to potential unauthorized data modifications. Additionally, attackers could leverage this vulnerability as a foothold for further attacks or to disrupt business continuity. Organizations with large user bases or those providing critical services through WordPress platforms are particularly vulnerable. The ease of exploitation without authentication increases the risk of automated attacks and widespread impact across multiple organizations.

Until an official patch is released, European organizations should implement strict access controls on the WordPress REST API endpoints, especially those related to user management. This can be achieved by restricting REST API access to authenticated and authorized users only, using plugins or custom code to enforce authorization checks. Monitoring and alerting on unusual user deletion activities should be established to detect potential exploitation attempts early. Network-level protections such as Web Application Firewalls (WAFs) can be configured to block suspicious REST API requests targeting user deletion endpoints. Organizations should also audit their user accounts regularly to identify unauthorized deletions or modifications. Once a patch is available, immediate upgrading of the Knowband Mobile App Builder plugin to version 3.0.0 or later is critical. Additionally, educating site administrators about this vulnerability and encouraging strong credential policies will help reduce risk.