CVE-2026-104739 in JS Help Desk Plugin
Summary
by MITRE • 10/30/2026
The JS Help Desk – AI-Powered Support & Ticketing System plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the setSupportCustomImage function in all versions up to, and including, 5.0.1. This makes it possible for authenticated attackers, with administrator-level access and above, to delete arbitrary files on the server, which can easily lead to remote code execution when the right file is deleted (such as wp-config.php). Exploitation requires a two-step sequence: an administrator first saves a traversal-crafted value in the support_custom_img configuration field, then triggers deletion by uploading a new support custom image, at which point setSupportCustomImage() resolves and deletes the attacker-controlled path.
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Analysis
by VulDB Data Team • 10/30/2026
The JS Help Desk plugin for WordPress contains a critical server-side file manipulation vulnerability within its administrative interface. Specifically, the function responsible for managing custom support images fails to adequately sanitize or validate user-supplied input before using it in filesystem operations. This flaw allows an authenticated attacker with administrator-level privileges to manipulate internal configuration values that dictate which files are processed by the application's backend logic. The severity of this vulnerability is amplified by its potential impact on system integrity, as the ability to delete arbitrary files can destabilize the entire WordPress installation or serve as a precursor to more severe compromises such as remote code execution.
The technical root cause lies in insufficient path validation within the setSupportCustomImage function. When an administrator interacts with the plugin's settings page, they are able to input values into the support_custom_img configuration field without rigorous checks against directory traversal sequences like dot-dot-slash. In a typical secure implementation, such inputs would be normalized and restricted to a predefined safe directory or validated against a whitelist of allowed filenames. However, in this vulnerable version up through 5.0.1, the application accepts these raw values and stores them directly into the database configuration without stripping dangerous path components. This lack of input validation creates a direct pathway for an attacker to influence server-side file operations using relative paths that escape the intended scope.
Exploitation of this vulnerability requires a two-step sequence due to how the plugin processes image uploads and configuration updates. First, the attacker must log in as an administrator and navigate to the JS Help Desk settings page to save a crafted value containing directory traversal characters into the support_custom_img field. This action persists the malicious path within the WordPress database options table. Second, the attacker triggers the deletion logic by uploading a new custom image through the designated upload interface. Upon processing this upload, the plugin invokes setSupportCustomImage(), which retrieves the previously stored configuration value and uses it to determine which file to delete or overwrite. Because the application does not validate that the resolved path remains within expected boundaries, it proceeds to execute the deletion command on whatever target is specified by the attacker-controlled variable.
The operational impact of this vulnerability extends beyond simple data loss. While deleting arbitrary files can disrupt service availability and corrupt plugin functionality, the most critical risk arises when an administrator targets sensitive configuration or script files. For instance, if an attacker deletes wp-config.php, which contains database credentials and security salts, the WordPress installation may become non-functional or revert to default insecure states depending on how other components handle missing configurations. More dangerously, in certain server environments or specific plugin interactions, deleting critical system files can lead to remote code execution. This occurs because many web applications rely on these core files for initialization; their absence might trigger fallback mechanisms that execute untrusted input or allow attackers to inject new malicious scripts into directories where the deleted file previously resided.
From a classification perspective, this vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory and CWE-650: Trust Boundary Violation. The failure to restrict user-controlled input from influencing filesystem paths is a classic example of path traversal leading to unauthorized file manipulation. In terms of the MITRE ATT&CK framework, this behavior corresponds to T1485: Data Destruction, where an adversary deletes data or disrupts availability by erasing specific files on local systems and network drives. The requirement for administrative access places this within the context of privilege escalation scenarios if lower-privileged users can eventually gain admin rights through other means, though currently it is strictly limited to those with existing high-level privileges.
Mitigation strategies should focus primarily on immediate patching and rigorous input validation practices. Administrators running versions up to 5.0.1 must update the JS Help Desk plugin to a patched version that implements proper path canonicalization and strict allow-listing for file operations. Developers reviewing similar codebases should ensure that all user inputs affecting filesystem paths are normalized using functions like realpath or equivalent secure abstractions before being passed to deletion commands. Additionally, implementing principle of least privilege by restricting the web server process's write permissions can limit the blast radius even if such a vulnerability is exploited in other plugins. Regular security audits and static code analysis tools configured to detect path traversal patterns can help identify similar flaws across WordPress ecosystems before they are deployed into production environments.