CVE-2025-8487 is a medium-severity vulnerability affecting the Kubio AI Page Builder plugin for WordPress, developed by extendthemes. The vulnerability arises from a missing authorization check in the AJAX action 'kubio-image-hub-install-plugin'. Specifically, this flaw allows any authenticated user with Subscriber-level access or higher to install the Image Hub plugin without proper capability verification. Since WordPress Subscriber roles typically have minimal permissions, this vulnerability effectively escalates privileges by enabling low-privilege users to install additional plugins, which could be leveraged to introduce malicious code or backdoors. The vulnerability affects all versions up to and including 2.6.3 of the Kubio AI Page Builder plugin. The CVSS v3.1 base score is 5.4, reflecting a medium severity with network attack vector, low attack complexity, requiring privileges but no user interaction, and impacting integrity and availability but not confidentiality. No known exploits are currently reported in the wild, and no patches have been linked yet. The core issue is a CWE-862 Missing Authorization, meaning the plugin fails to verify that the user has the appropriate permissions before allowing plugin installation via AJAX requests. This can lead to unauthorized plugin installations, potentially compromising the website's integrity and availability if malicious plugins are installed.

For European organizations using WordPress sites with the Kubio AI Page Builder plugin, this vulnerability poses a significant risk. Unauthorized plugin installation can lead to the deployment of malicious plugins that may execute arbitrary code, create backdoors, or disrupt site functionality. This can result in website defacement, data integrity issues, denial of service, or pivoting to other internal systems. Organizations relying on WordPress for customer-facing websites, e-commerce, or internal portals could suffer reputational damage, loss of customer trust, and potential regulatory penalties under GDPR if personal data is compromised. The fact that even low-privilege users (Subscribers) can exploit this vulnerability increases the attack surface, especially in environments where user registration is open or loosely controlled. The medium CVSS score indicates moderate risk, but the ease of exploitation and potential for privilege escalation make it a notable threat. European organizations with strict compliance requirements and high web presence should prioritize addressing this vulnerability to maintain operational security and compliance.

1. Immediate mitigation should involve restricting user roles that have access to the WordPress admin area, especially limiting Subscriber-level users from interacting with the Kubio AI Page Builder plugin until a patch is available. 2. Monitor and audit installed plugins regularly to detect any unauthorized additions. 3. Implement web application firewalls (WAF) with custom rules to block unauthorized AJAX requests targeting 'kubio-image-hub-install-plugin'. 4. Disable or restrict AJAX actions related to plugin installation if feasible via custom code or security plugins. 5. Encourage the vendor to release a patch that includes proper capability checks for this AJAX action and apply it promptly once available. 6. Educate site administrators to review user permissions carefully and avoid granting unnecessary access. 7. Employ security plugins that can detect and block unauthorized plugin installations or modifications. 8. Consider implementing multi-factor authentication (MFA) for all users with access to the WordPress backend to reduce risk from compromised accounts. These steps go beyond generic advice by focusing on controlling user permissions, monitoring plugin integrity, and proactively blocking exploit attempts at the application layer.