CVE-2026-75919 in phpMyFAQ
Summary
by MITRE • 08/19/2026
phpMyFAQ before 4.1.7 contains an authentication bypass vulnerability in SetupController that allows unauthenticated attackers to run database migrations and create configuration backups when maintenance mode is enabled. Attackers can call POST /api/setup/update-database and POST /api/setup/backup endpoints to execute database updates, disable maintenance mode, and extract database credentials from generated ZIP archives.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in phpMyFAQ versions prior to 4.1.7 represents a critical authentication bypass within the SetupController component of the application. This flaw specifically exploits the logic governing the maintenance mode feature, which is typically intended as an administrative tool for system updates and configuration management rather than public-facing functionality. When maintenance mode is enabled, the application incorrectly assumes that only authorized administrators will interact with setup-related endpoints. However, due to insufficient access control checks on specific API routes, unauthenticated attackers can bypass these restrictions entirely. This misconfiguration allows external actors to execute privileged operations without providing valid credentials or session tokens, fundamentally undermining the security model of the content management system.
The technical core of this vulnerability lies in the improper validation of request origins and user states for two distinct endpoints: POST /api/setup/update-database and POST /api/setup/backup. The update-database endpoint allows attackers to trigger database migrations, which can alter schema structures or inject malicious data depending on the migration scripts available. More critically, the backup endpoint enables the generation of configuration archives containing sensitive system parameters. Because these actions are accessible without authentication when maintenance mode is active, an attacker with network access to the server can initiate these processes remotely. The lack of cryptographic verification or challenge-response mechanisms further exacerbates the risk, allowing automated exploitation tools to interact with these endpoints freely.
The operational impact of this vulnerability is severe and multifaceted. By executing database migrations, attackers may disrupt service availability or manipulate data integrity within the application's backend storage. However, the most damaging consequence stems from the ability to create configuration backups via the backup endpoint. These ZIP archives typically contain plaintext credentials for database connections, API keys, and other sensitive configuration details required for the phpMyFAQ instance to function. Once an attacker extracts these files, they gain full administrative control over both the web application and its underlying database infrastructure. This leads to a complete compromise of confidentiality, integrity, and availability, as the extracted credentials can be used to access backend systems directly or escalate privileges within other connected services.
From a classification perspective, this vulnerability aligns with CWE-287, which describes Improper Authentication, specifically involving bypassing mechanisms intended for administrative functions. It also relates closely to CWE-613, Insufficient Session Expiration, as the maintenance mode effectively creates an extended window of opportunity for unauthorized access if not properly monitored and restricted by IP whitelisting or other network-level controls. In terms of offensive security frameworks, this exploit maps to MITRE ATT&CK technique T1078, Valid Accounts, where attackers leverage misconfigured permissions to gain initial access, followed by T1505.003, Server Software Component: Web Shell, if the database manipulation leads to code execution capabilities through stored procedures or similar mechanisms.
Mitigation strategies must focus on immediate remediation and architectural hardening. The primary solution is to upgrade phpMyFAQ to version 4.1.7 or later, where these access control flaws have been addressed by developers. For systems that cannot be immediately patched, administrators should disable maintenance mode when not actively performing updates, as this removes the attack vector entirely. Additionally, implementing strict IP whitelisting for all setup and administrative endpoints is crucial to ensure that only trusted management networks can interact with sensitive API routes. Network-level firewalls or Web Application Firewalls (WAF) should be configured to block unauthorized POST requests to /api/setup paths from external sources. Regular auditing of configuration backups and credential rotation policies are also recommended to minimize the blast radius in case of future incidents, ensuring that even if credentials are exposed, their utility is limited by short expiration times or multi-factor authentication requirements on dependent services.