CVE-2026-16292 in Frontend File Manager Plugin
Summary
by MITRE • 08/02/2026
The Frontend File Manager Plugin WordPress plugin through 23.6 does not perform nonce validation on one of its file-metadata update actions, allowing an attacker to modify the metadata of a logged-in user's uploaded file via a CSRF attack, which can be leveraged to download that file. When guest uploads are enabled, the same action is reachable unauthenticated against any user's file.
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Analysis
by VulDB Data Team • 08/02/2026
The Frontend File Manager Plugin for WordPress represents a widely used tool that enables users to manage files directly through the frontend interface of websites. This plugin allows users to upload, organize, and manipulate various types of files while providing metadata management capabilities. The vulnerability under discussion affects versions up to 23.6 and specifically targets the plugin's file-metadata update functionality. The core issue lies in the absence of proper nonce validation within one of the plugin's critical actions, creating a significant security gap that can be exploited through cross-site request forgery attacks.
The technical flaw manifests as a missing input validation mechanism within the plugin's backend processing logic. When users perform file metadata updates through the frontend interface, the system should verify that the request originates from a legitimate authenticated session by checking a cryptographic nonce value. However, this validation step has been omitted, allowing attackers to construct malicious requests that appear to come from valid user sessions. The absence of nonce verification creates a predictable attack surface where unauthorized modifications can be made to file metadata without proper authorization.
The operational impact of this vulnerability extends beyond simple metadata manipulation and presents a severe risk to file confidentiality and integrity. Attackers who successfully exploit this CSRF vulnerability can modify file metadata in ways that may enable them to bypass normal access controls and potentially download files they would not otherwise have permission to access. When guest uploads are enabled, the attack surface becomes even more expansive as the same vulnerable endpoint becomes accessible without authentication, allowing attackers to target any user's uploaded files regardless of their session status.
This vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery issues in web applications. The flaw represents a classic CSRF attack vector where an attacker can manipulate a victim's browser into performing unintended actions on a web application while the victim is authenticated. The ATT&CK framework categorizes this as a privilege escalation technique through web application vulnerabilities, potentially allowing attackers to gain unauthorized access to sensitive data. The vulnerability demonstrates poor input validation practices and inadequate session management controls within the WordPress plugin ecosystem.
The security implications of this issue become particularly concerning when considering that file metadata modifications can include changes to file permissions, access controls, or other attributes that may affect file accessibility. An attacker could potentially manipulate metadata to make files publicly accessible or modify their attributes in ways that facilitate further exploitation. When combined with guest upload capabilities, the vulnerability transforms from a session-based attack into a more dangerous unauthenticated threat vector, significantly increasing the potential impact and attack surface.
Mitigation strategies should focus on immediate implementation of proper nonce validation mechanisms within the plugin's file metadata update endpoints. WordPress developers should ensure that all actions requiring user authentication include robust verification steps using cryptographic nonces generated per session. The plugin should also implement additional access control checks to verify that users can only modify metadata for files they actually own or have explicit permissions to modify. Regular security audits of plugin code should be conducted to identify similar validation gaps, and developers should follow established WordPress security guidelines for handling user inputs and session management.
Organizations using this plugin should immediately update to versions that address the identified CSRF vulnerability while implementing additional monitoring measures to detect unauthorized file metadata modifications. Network segmentation and proper access controls should be maintained to limit exposure even when plugins contain vulnerabilities. Security teams should also consider implementing automated scanning tools that can identify similar CSRF patterns in custom plugin development and ensure that all user-facing actions include proper authentication verification mechanisms. The vulnerability highlights the importance of following secure coding practices and maintaining regular security updates for all WordPress plugins, particularly those handling file operations and user data management functions.
The presence of such vulnerabilities in popular WordPress plugins underscores the need for comprehensive security awareness among developers and site administrators. This particular flaw demonstrates how seemingly minor implementation gaps can create significant security risks that may be exploited to compromise entire websites. Regular security assessments and adherence to established security frameworks remain essential practices for maintaining robust defenses against sophisticated attack vectors that exploit these types of validation weaknesses in web applications.