CVE-2026-103440 in PageTriage Extension
Summary
by MITRE • 09/30/2026
Exposure of sensitive information through data queries vulnerability in The Wikimedia Foundation MediaWiki PageTriage extension allows Information Elicitation.
This issue affects MediaWiki PageTriage extension: 1.46, 1.45, and 1.43.
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Analysis
by VulDB Data Team • 09/30/2026
The identified vulnerability within the Wikimedia Foundation's MediaWiki PageTriage extension represents a critical information disclosure flaw that stems from improper access controls governing data queries. This security issue specifically impacts versions 1.46, 1.45, and 1.43 of the extension. The core technical deficiency lies in the application's handling of user input during database query operations, where insufficient validation or authorization checks allow an attacker to manipulate requests to retrieve sensitive information that should remain restricted. This type of vulnerability is classically categorized under CWE-209, which describes the generation of error messages containing sensitive information, and more broadly aligns with CWE-284, indicating improper access control. The flaw enables what is technically referred to as Information Elicitation, a technique where an attacker interacts with the system in ways designed to reveal hidden data through side channels or direct query manipulation rather than exploiting a logic error that causes immediate crash or code execution.
From an operational perspective, this vulnerability allows unauthorized users to potentially access private user data, internal configuration details, or other restricted content stored within the MediaWiki database. In the context of Wikimedia projects, which host vast amounts of public and semi-public information, the exposure of sensitive metadata can compromise user privacy and system integrity. Attackers could leverage this flaw to map out the underlying database structure, identify high-value targets such as administrators or users with specific permissions, or extract data that is not intended for general consumption. This capability significantly lowers the barrier for further attacks, as it provides adversaries with contextual intelligence necessary for crafting more sophisticated exploits, including privilege escalation or targeted social engineering campaigns against site contributors and maintainers.
The attack vector associated with this vulnerability typically involves HTTP requests directed at specific API endpoints or internal pages managed by the PageTriage extension. By carefully constructing queries that exploit the lack of proper authorization checks, an attacker can trigger responses that leak data through error messages, response timing differences, or direct content exposure. This aligns with MITRE ATT&CK technique T1078, Valid Accounts, if the vulnerability allows access to resources restricted to authenticated users, and potentially T1539, Steal Web Session Cookie, if session tokens are inadvertently exposed during the query process. The persistence of this flaw across multiple recent versions suggests a systemic issue in how the extension validates user permissions before executing database operations, highlighting a gap in the secure development lifecycle for these specific releases.
Mitigation strategies must prioritize immediate patching to the latest stable version of the MediaWiki PageTriage extension where this vulnerability has been addressed by the maintainers. In environments where upgrading is not immediately feasible, administrators should implement strict web application firewall rules that monitor and filter anomalous query patterns associated with information elicitation attacks. Additionally, ensuring that detailed error messages are suppressed in production environments can reduce the effectiveness of certain data extraction techniques. Regular security audits focusing on access control logic within custom extensions are essential to prevent similar flaws from persisting or emerging in future updates. Maintaining a rigorous patch management policy and validating all user inputs against expected formats and permissions will significantly harden the MediaWiki installation against this class of information disclosure vulnerabilities.