The vulnerability identified as CVE-2026-24421 affects phpMyFAQ, an open-source FAQ web application, specifically versions 4.0.14 and earlier. The issue arises from improper authorization logic in the SetupController.php file, where the /api/setup/backup endpoint only verifies that a user is authenticated (via userIsAuthenticated()) but fails to confirm if the user possesses the necessary administrative or configuration permissions. Consequently, any authenticated user, regardless of their privilege level, can invoke this endpoint to trigger a backup of the application's configuration and receive a URL pointing to the generated ZIP archive containing sensitive configuration data. This exposure can lead to unauthorized disclosure of configuration details, potentially aiding attackers in further exploitation or reconnaissance. The vulnerability is classified under CWE-862 (Missing Authorization) and has a CVSS 3.1 base score of 6.5, reflecting a medium severity impact primarily on confidentiality. The flaw does not affect data integrity or system availability and does not require user interaction beyond authentication. No known exploits are currently reported in the wild. The issue was addressed and fixed in phpMyFAQ version 4.0.17 by implementing proper authorization checks to ensure only users with appropriate admin rights can access the backup functionality.

For European organizations using phpMyFAQ versions below 4.0.17, this vulnerability poses a significant confidentiality risk. Unauthorized users with valid credentials—potentially low-privileged internal users or compromised accounts—can access sensitive configuration backups, which may contain database credentials, API keys, or other critical information. This exposure could facilitate further attacks such as privilege escalation, lateral movement, or data exfiltration. While the vulnerability does not directly impact system integrity or availability, the leakage of configuration data can undermine overall security posture and trustworthiness of the affected systems. Organizations in sectors with strict data protection regulations, such as finance, healthcare, or government, could face compliance issues if sensitive data is exposed. Additionally, attackers leveraging this vulnerability might gain insights into the infrastructure, increasing the risk of targeted attacks. The medium severity rating indicates a moderate but actionable threat that should be addressed promptly to prevent potential exploitation.

European organizations should immediately upgrade phpMyFAQ installations to version 4.0.17 or later, where the authorization flaw is corrected. Until the upgrade can be performed, restrict access to the /api/setup/backup endpoint by implementing network-level controls such as IP whitelisting or firewall rules limiting access to trusted administrative networks. Review and enforce strict user role definitions within phpMyFAQ to minimize the number of authenticated users with access to sensitive functions. Conduct an audit of user accounts to identify and disable or remove unnecessary or inactive accounts. Monitor access logs for unusual or unauthorized attempts to invoke the backup endpoint. Additionally, consider implementing web application firewalls (WAFs) with custom rules to detect and block unauthorized access attempts to this endpoint. Regularly review and update security policies to ensure that authentication and authorization mechanisms are properly configured and tested. Finally, educate administrators and users about the importance of using strong, unique credentials to reduce the risk of account compromise.