CVE-2026-111884 in phpMyFAQ
Summary
by MITRE • 10/17/2026
phpMyFAQ before 4.1.9 and 4.2.0-alpha before 4.2.0-beta does not require the current password when changing an account e-mail in the user control panel (UserController::updateData, api/user/data/update), checking only the session and CSRF token. An attacker with a hijacked session can set the e-mail to their own mailbox and use the password-reset flow to take over non-2FA accounts, including superadmin.
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Analysis
by VulDB Data Team • 10/17/2026
The vulnerability identified in phpMyFAQ versions prior to 4.1.9 and version 4.2.0-alpha before 4.2.0-beta represents a critical authentication bypass flaw within the user account management subsystem. Specifically, the issue resides in the UserController::updateData endpoint as well as the corresponding API route for updating user data at api/user/data/update. The core technical deficiency is that when an authenticated user attempts to modify their associated email address through the control panel or API interface, the system fails to validate the current password of the account holder. Instead, the application relies exclusively on the presence of a valid session cookie and a correct Cross-Site Request Forgery (CSRF) token to authorize this sensitive change. This design decision fundamentally undermines the principle of least privilege by allowing any actor who possesses an active session to alter critical identity attributes without proving continued knowledge of the account credentials.
From a technical perspective, this flaw aligns with CWE-287, which describes Improper Authentication, and more specifically relates to insufficient verification mechanisms for sensitive state changes. In secure application design, modifying high-risk profile data such as an email address should require re-authentication via password entry or multi-factor authentication to ensure that the request originates from the legitimate account owner rather than a session hijacker. By omitting this step, phpMyFAQ creates a direct pathway for attackers who have compromised user sessions through techniques like Cross-Site Scripting (XSS), network sniffing on unencrypted connections, or cookie theft via malicious browser extensions to escalate their access level. The reliance solely on CSRF tokens is insufficient because many session hijacking vectors do not trigger the same-origin policy protections that typically guard against cross-site requests; if an attacker can inject JavaScript into a page viewed by the victim while they are logged in, they may be able to forge valid-looking requests with the correct CSRF token but without knowing the password.
The operational impact of this vulnerability is severe, particularly for administrative accounts and users who do not employ two-factor authentication (2FA). An attacker leveraging a hijacked session can change the account email address to one under their control. Once the email is updated, the attacker utilizes the standard password reset functionality provided by phpMyFAQ. Since the system sends recovery links or codes to the newly set email address, and that inbox is controlled by the attacker, they can seamlessly reset the account password. This sequence effectively results in a complete account takeover (ATO). For superadmin accounts, this compromise grants full control over the entire knowledge base platform, including the ability to modify content, manage other users, and potentially exploit further vulnerabilities within the administrative interface. The risk is amplified for organizations using phpMyFAQ as a central repository of sensitive information or internal documentation.
This attack chain maps directly to several techniques in the MITRE ATT&CK framework. The initial access phase involves Session Hijacking (T1539), where the attacker steals valid session tokens. The subsequent action corresponds to Account Manipulation (T1098) via Email Address Modification, followed by Credential Access through Password Reset Abuse (T1621). This combination allows an adversary to maintain persistent access and evade detection mechanisms that might otherwise flag unusual login locations or behaviors if the original password remained unchanged until the final reset step. The lack of multi-factor authentication for such a critical action means there is no secondary barrier to stop this progression, making it a high-severity issue requiring immediate remediation.
To mitigate this vulnerability, developers must enforce re-authentication for any operation that modifies sensitive account attributes like email addresses or passwords. This can be achieved by requiring the user to enter their current password before processing the update request in both the web interface and API endpoints. Alternatively, implementing a step-up authentication flow using time-based one-time passwords (TOTP) or other multi-factor methods would significantly raise the barrier for attackers who have only obtained session cookies. Additionally, ensuring that CSRF tokens are bound tightly to specific user actions and sessions is essential, though this alone does not resolve the issue of stolen valid sessions. Upgrading to phpMyFAQ version 4.1.9 or later resolves this flaw by implementing proper password verification during email changes. Organizations running affected versions should immediately apply patches and review access logs for any suspicious account modifications that may indicate exploitation in their environment.