CVE-2026-111897 in phpMyFAQ
Summary
by MITRE • 10/17/2026
phpMyFAQ 4.2.0-alpha before 4.2.0-beta contains an authorization bypass vulnerability that allows category-restricted editors to manage attachments of FAQs outside their categories by supplying arbitrary record IDs. Attackers in medium permission mode can send upload or delete requests with a target record_id or attachment ID to tamper with or remove files on unauthorized FAQs.
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Analysis
by VulDB Data Team • 10/18/2026
The identified security flaw resides within phpMyFAQ versions prior to 4.2.0-beta, specifically affecting the release candidate phase starting from version 4.2.0-alpha. This vulnerability is classified as an authorization bypass, which fundamentally undermines the access control mechanisms designed to restrict user actions based on their assigned roles and permissions. In a typical content management system like phpMyFAQ, editors are often granted specific scopes of authority, such as managing only those FAQ entries that belong to categories they have been explicitly authorized to edit. This principle is critical for maintaining data integrity and preventing unauthorized modifications in multi-user environments where different teams or individuals manage distinct sections of the knowledge base.
The technical root cause of this vulnerability lies in the insufficient validation of record identifiers during file management operations. When a user with medium-level permissions attempts to upload or delete an attachment, the application fails to verify whether the target FAQ entry associated with that attachment actually belongs to one of the categories permitted for that specific editor. Instead of checking the category ownership against the user's permission set, the system relies solely on the provided record ID or attachment ID supplied in the request payload. This lack of server-side authorization checks allows an attacker to manipulate these identifiers directly, effectively bypassing the intended logical access controls.
From a technical perspective, this flaw aligns with CWE-284, which describes Improper Access Control, and specifically relates to CWE-639, Authorization Bypass Through User-Controlled Key. The vulnerability enables what is known as an Insecure Direct Object Reference (IDOR) scenario where the internal identifier for a resource is exposed and used directly without proper validation of the requester's relationship to that resource. By supplying arbitrary record IDs in upload or delete requests, an attacker can target FAQs outside their designated scope. This behavior mirrors techniques observed in MITRE ATT&CK framework under T1078, Valid Accounts, as it involves leveraging legitimate credentials with limited privileges to perform actions beyond those permissions through manipulation of input parameters rather than exploiting a software bug in the authentication mechanism itself.
The operational impact of this vulnerability is significant for organizations relying on phpMyFAQ for secure knowledge management. An attacker can tamper with or remove files associated with FAQs that they are not authorized to edit. This capability leads directly to data integrity violations, as critical documentation may be altered or deleted by unauthorized personnel. Furthermore, the ability to upload arbitrary attachments could potentially lead to further security compromises if malicious files are introduced into the system's storage directory, although the primary immediate risk is the disruption of service and loss of accurate information due to unauthorized deletions or modifications. The severity is generally considered medium because it requires authenticated access with at least editor-level permissions, but the ease of exploitation via simple parameter manipulation makes it a persistent threat in poorly configured environments.
To mitigate this vulnerability, administrators must upgrade phpMyFAQ to version 4.2.0-beta or any later stable release where these authorization checks have been implemented correctly. In addition to upgrading, organizations should enforce strict input validation on the server side for all file management endpoints, ensuring that every request is cross-referenced against a secure session store containing user permissions and category assignments. Implementing robust access control lists (ACLs) at the application logic level rather than relying solely on UI restrictions can prevent such bypasses. Regular security audits focusing on IDOR vulnerabilities are also recommended to ensure that all resource identifiers are properly validated before processing any state-changing operations.