CVE-2026-44642 in Piwigo
Summary
by MITRE • 09/25/2026
Piwigo is a full featured open source photo gallery application for the web. Prior to 16.4.0, check_upgrade_access_rights() in admin/include/functions_upgrade.php conditionally escapes the submitted username only when the removed get_magic_quotes_gpc function exists, so PHP 8 and later concatenate an unauthenticated username directly into the upgrade authentication SQL query. When database upgrades are pending, a crafted query result can satisfy the status and password checks, set PHPWG_IN_UPGRADE, and authorize upgrade execution without valid administrator credentials. This can cause unauthorized database integrity changes and service disruption. This vulnerability is fixed in 16.4.0.
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Analysis
by VulDB Data Team • 09/25/2026
Piwigo serves as a comprehensive open-source photo gallery application designed for web deployment, offering extensive features for managing digital media collections. A critical security flaw was identified within the administrative upgrade mechanism prior to version 16.4.0, specifically residing in the check_upgrade_access_rights function located in admin/include/functions_upgrade.php. This vulnerability stems from an improper handling of user input during database integrity checks and authentication processes, leading to a severe bypass of access controls that should restrict administrative actions to authorized personnel only.
The technical root cause involves a conditional logic error related to PHP version compatibility. The application attempts to escape submitted usernames by checking for the existence of the deprecated get_magic_quotes_gpc function. In modern environments running PHP 8 and later, this function is no longer present or active due to its removal from the language core. Consequently, when such an environment executes the upgrade check routine, the username input remains unescaped. This lack of sanitization allows attackers to inject malicious SQL payloads directly into the authentication query used during the upgrade process.
The operational impact of this vulnerability is significant because it enables unauthorized database modifications and potential service disruption. When pending database upgrades exist within a Piwigo installation, an attacker can craft specific input that satisfies both the status verification and password validation checks without possessing valid administrator credentials. By successfully bypassing these authentication barriers, the application sets the PHPWG_IN_UPGRADE flag to true, thereby authorizing the execution of upgrade scripts. This effectively grants the attacker administrative privileges over the underlying database structure, allowing for integrity changes that can compromise data confidentiality, alter gallery configurations, or render the service unavailable through destructive operations.
This vulnerability aligns with Common Weakness Enumeration CWE-89, which classifies Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. Furthermore, from a tactical perspective within the MITRE ATT&CK framework, this exploit maps to techniques involving Unauthorized Access via Authentication Bypass and potentially T1053 Scheduled Task/Job for executing malicious database scripts if upgrade routines include destructive commands. The flaw highlights the risks associated with maintaining legacy compatibility code that fails to account for modern PHP environments where deprecated security features are absent by default.
To mitigate this risk, organizations running Piwigo must immediately update their installations to version 16.4.0 or later, which contains the necessary patches to properly sanitize input regardless of the underlying PHP version. For systems unable to upgrade instantly due to operational constraints, temporary mitigations include restricting access to the administrative interface through network-level controls such as firewalls or IP whitelisting, ensuring that only trusted internal addresses can reach the admin endpoints. Additionally, deploying a Web Application Firewall with robust SQL injection detection rules may help block exploit attempts by identifying and filtering malformed query structures before they interact with the database layer. Regular auditing of application logs for unusual authentication patterns related to upgrade processes is also recommended to detect any potential exploitation activity in legacy environments.