The Kubio AI Page Builder plugin for WordPress suffers from a missing authorization vulnerability (CWE-862) identified as CVE-2025-8487. Specifically, the AJAX action 'kubio-image-hub-install-plugin' lacks proper capability checks, allowing any authenticated user with Subscriber-level access or higher to install the Image Hub plugin without authorization. This vulnerability exists in all versions up to and including 2.6.3. Since WordPress roles like Subscriber are typically assigned to minimally privileged users, this flaw significantly lowers the barrier for privilege escalation via unauthorized plugin installation. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), and only requires privileges (PR:L) but no user interaction (UI:N). The vulnerability impacts the integrity and availability of the affected WordPress site by enabling unauthorized plugin installation, which could lead to further compromise or service disruption. No patches are currently linked, and no known exploits have been reported in the wild as of the publication date. The vulnerability was reserved on August 1, 2025, and published on September 19, 2025, by Wordfence. The CVSS v3.1 base score is 5.4, indicating medium severity. The issue highlights the importance of enforcing strict capability checks on AJAX actions within WordPress plugins to prevent unauthorized operations.

This vulnerability can allow low-privileged authenticated users to install plugins without proper authorization, potentially leading to unauthorized code execution, site defacement, or denial of service if malicious plugins are installed. The integrity of the website is compromised as attackers can alter the plugin landscape, and availability may be affected if the installed plugins disrupt normal site operations. Although confidentiality is not directly impacted, the unauthorized plugin installation could be a stepping stone for further attacks that compromise sensitive data. Organizations relying on the Kubio AI Page Builder plugin are at risk of unauthorized modifications to their WordPress environment, which can undermine trust, cause downtime, and lead to costly remediation efforts. The ease of exploitation and the broad user base of WordPress increase the potential attack surface globally.

1. Immediately update the Kubio AI Page Builder plugin to a patched version once available from the vendor. 2. Until a patch is released, restrict access to the WordPress admin area and AJAX endpoints to trusted users only, using web application firewalls or IP whitelisting. 3. Implement strict role management policies to minimize the number of users with Subscriber-level or higher access. 4. Monitor WordPress logs for unusual plugin installation activities or AJAX requests to 'kubio-image-hub-install-plugin'. 5. Employ security plugins that enforce capability checks and block unauthorized AJAX actions. 6. Conduct regular security audits of installed plugins and user roles to detect unauthorized changes. 7. Educate site administrators about the risks of granting unnecessary privileges and the importance of timely updates. 8. Consider disabling AJAX actions related to plugin installation if not required for site functionality.