CVE-2026-39792 in Simple File List Plugin
Summary
by MITRE • 10/06/2026
Unauthenticated Arbitrary File Deletion in Simple File List <= 6.3.11 versions.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as an unauthenticated arbitrary file deletion flaw within the Simple File List plugin, specifically affecting versions up to and including 6.3.11, represents a critical security deficiency that compromises the integrity of the underlying web server infrastructure. This issue stems from insufficient input validation and improper handling of user-supplied data in functions responsible for managing file operations. The core technical flaw lies in the application's failure to adequately sanitize or validate filenames provided by users before processing deletion requests. In many implementations of such plugins, developers may rely on assumptions about the structure of uploaded files or trust that directory traversal sequences are blocked by default server configurations rather than implementing robust validation logic within the application code itself. This oversight allows an attacker to manipulate file paths using relative path notation, effectively bypassing intended access controls and targeting arbitrary locations on the filesystem where the web server process has write permissions.
From a technical perspective, this vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory, often coupled with CWE-94: Improper Control of Generation of Code (Path Traversal). The exploitation mechanism typically involves constructing a malicious HTTP request where the file parameter contains directory traversal sequences such as dot-dot-slash. By carefully crafting these requests, an attacker can navigate outside the designated upload or plugin directories and target sensitive system files, configuration files, or other critical components stored in accessible locations on the server. Because this operation is unauthenticated, it does not require any form of user credentials, making it particularly dangerous as it can be exploited by anonymous attackers scanning for vulnerable instances across the internet without needing to bypass login mechanisms first.
The operational impact of successfully exploiting this vulnerability extends beyond simple data loss. An attacker who achieves arbitrary file deletion can disrupt service availability by removing essential configuration files or core application components, leading to a denial of service condition. Furthermore, if critical security-related files are deleted, it may inadvertently weaken the overall security posture of the web server, potentially exposing other vulnerabilities that were previously mitigated by those configurations. In severe cases, depending on how the remaining system behaves after file removal, an attacker might be able to facilitate further attacks such as remote code execution or privilege escalation if subsequent processes fail in unexpected ways due to missing dependencies. The ability to delete files without authentication significantly lowers the barrier for entry, allowing even low-skilled threat actors to cause substantial damage using automated scanning tools commonly found in cybercrime toolkits.
To mitigate this risk, immediate action is required by administrators running affected versions of Simple File List. The primary recommendation is to upgrade the plugin to a version newer than 6.3.11 where these input validation issues have been addressed by the developers. If upgrading is not immediately feasible due to compatibility constraints or other operational reasons, temporary mitigations should be implemented at the web server level. This includes configuring strict file permissions so that the web server process does not have write access to directories outside of designated upload folders. Additionally, implementing a Web Application Firewall with rules specifically designed to detect and block directory traversal attempts can provide an additional layer of defense against exploitation. Regular monitoring of server logs for unusual deletion patterns or errors related to missing files is also advised to ensure early detection of any attempted exploits.