The vulnerability identified as CVE-2026-24421 affects phpMyFAQ, an open-source FAQ web application, specifically versions prior to 4.0.17. The root cause is a missing authorization check in the SetupController.php file, where the /api/setup/backup endpoint only verifies if a user is authenticated via userIsAuthenticated(), but does not confirm if the user has the necessary administrative or configuration permissions. This allows any authenticated user, including those with limited privileges, to invoke the backup functionality and retrieve a link to a ZIP file containing configuration backups. Since the backup may contain sensitive information such as database credentials, configuration settings, or other internal data, unauthorized access could lead to confidentiality breaches. The CVSS 3.1 score is 6.5 (medium), reflecting that the attack vector is network-based, requires low privileges, no user interaction, and impacts confidentiality but not integrity or availability. The vulnerability does not require user interaction and affects all installations running vulnerable versions exposed to authenticated users. The flaw was addressed in version 4.0.17 by adding proper authorization checks to ensure only users with admin rights can access the backup endpoint.

For European organizations using phpMyFAQ versions below 4.0.17, this vulnerability poses a significant risk of unauthorized disclosure of sensitive configuration data. Exposure of backup files could lead to leakage of database credentials, internal configuration details, or other sensitive information that attackers could leverage for further compromise or lateral movement within the network. This is particularly critical for organizations that rely on phpMyFAQ to manage internal knowledge bases or customer support information, as the confidentiality of their infrastructure could be undermined. The vulnerability does not directly affect system integrity or availability but can facilitate subsequent attacks. Given the medium CVSS score and the ease of exploitation by any authenticated user, organizations with weak access controls or publicly accessible authentication endpoints are at higher risk. The impact is amplified in sectors with strict data protection regulations such as GDPR, where unauthorized data exposure can lead to regulatory penalties and reputational damage.

Organizations should immediately upgrade phpMyFAQ installations to version 4.0.17 or later, where the authorization checks have been properly implemented. Until the upgrade can be performed, restrict access to the /api/setup/backup endpoint by implementing network-level controls such as IP whitelisting or VPN-only access. Review and tighten user privilege assignments to ensure that only trusted administrators have authentication credentials capable of accessing the backup functionality. Monitor access logs for unusual or unauthorized backup requests. Additionally, consider implementing web application firewalls (WAFs) with custom rules to detect and block unauthorized API calls to the backup endpoint. Conduct regular audits of configuration backups to ensure no sensitive data is unnecessarily exposed. Finally, educate administrators and users about the importance of applying security patches promptly.