CVE-2026-57311 in Windu CMS
Summary
by MITRE • 07/20/2026
Windu CMS does not validate types of uploaded files. An authenticated attacker can upload arbitrary files, including PHP. This can lead to Remote Code Execution.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 4.1 but may also affect other versions.
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Analysis
by VulDB Data Team • 07/20/2026
Windu CMS suffers from a critical security flaw that stems from inadequate file type validation during the upload process, creating a pathway for authenticated attackers to execute remote code on affected systems. This vulnerability exists within the content management platform's file handling mechanisms where the application fails to properly verify the actual MIME type or file extension of uploaded content, allowing malicious users with valid credentials to bypass security controls and introduce arbitrary files including web shell scripts.
The technical implementation of this vulnerability resides in the application's upload functionality which lacks proper input sanitization and validation routines. When an authenticated user attempts to upload a file, the system should verify that the uploaded content matches the expected file type based on its MIME header or file extension, but Windu CMS fails to perform these critical checks. This oversight enables attackers to upload PHP files with malicious code that can be executed by the web server, effectively providing them with remote command execution capabilities on the target system.
The operational impact of this vulnerability is severe and multifaceted, as it allows attackers to escalate their privileges from authenticated user access to full system control without requiring additional authentication methods or exploitation techniques. Once an attacker successfully uploads a PHP payload, they can execute arbitrary commands on the server, potentially leading to data exfiltration, system compromise, privilege escalation, and further network infiltration. The vulnerability affects any version where the upload functionality is implemented without proper validation, with version 4.1 confirmed as vulnerable but likely other versions may exhibit similar behavior due to the fundamental nature of the missing security controls.
From a cybersecurity perspective, this vulnerability aligns with CWE-434 which describes "Unrestricted Upload of File with Dangerous Type" and represents a classic example of insecure file upload handling that enables remote code execution. The attack pattern follows typical adversary techniques documented in the MITRE ATT&CK framework under T1190 for "Exploit Public-Facing Application" and T1059 for "Command and Scripting Interpreter" as attackers leverage the uploaded malicious files to execute commands on the compromised system. Organizations using Windu CMS should immediately implement mitigations including restricting file upload capabilities, implementing strict MIME type validation, employing file content analysis, and conducting thorough security reviews of all upload mechanisms.
The lack of vendor response to vulnerability disclosure attempts further compounds the risk for affected organizations, as they may not receive timely patches or updates to address this critical flaw. Security teams should consider deploying network-based intrusion detection systems to monitor for suspicious file upload activities and implement web application firewalls that can detect and block malicious file upload attempts. Additionally, regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other applications and services within the organization's attack surface, as this type of vulnerability often indicates broader security weaknesses in the application development lifecycle that may affect other components beyond just the file upload functionality.