CVE-2026-2666 in MCMS
Summary
by MITRE • 02/18/2026
A flaw has been found in mingSoft MCMS 6.1.1. The affected element is an unknown function of the file /ms/file/uploadTemplate.do of the component Template Archive Handler. Executing a manipulation of the argument File can lead to unrestricted upload. The attack can be launched remotely. The exploit has been published and may be used.
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Analysis
by VulDB Data Team • 02/21/2026
The vulnerability identified as CVE-2026-2666 resides within the mingSoft MCMS 6.1.1 content management system, specifically targeting the Template Archive Handler component. This flaw manifests in the /ms/file/uploadTemplate.do endpoint which processes file upload operations for template archives. The vulnerability stems from inadequate input validation mechanisms within an unknown function that handles the File argument parameter. Security researchers have determined that this weakness allows for unrestricted file upload capabilities, representing a critical security flaw that can be exploited without requiring authentication or physical access to the target system. The remote exploitability of this vulnerability means that attackers can leverage it from any network location, making it particularly dangerous for publicly accessible web applications.
The technical implementation of this vulnerability involves a failure in the file upload validation process where the system does not properly sanitize or verify the file type, size, or content before processing the upload request. This allows malicious actors to upload arbitrary files, potentially including malicious scripts or executables, to the target server. The attack vector operates through manipulation of the File argument parameter in the uploadTemplate.do endpoint, bypassing normal security controls that should prevent the upload of potentially harmful content. The published exploit demonstrates that this vulnerability can be reliably leveraged by threat actors to achieve unauthorized file execution on the affected system, potentially leading to complete system compromise.
From an operational impact perspective, this vulnerability creates significant risk for organizations using mingSoft MCMS 6.1.1 as it can enable attackers to establish persistent backdoors, deploy malware, or execute arbitrary code on the target server. The unrestricted upload capability means that malicious files can be uploaded and executed without detection, potentially leading to data breaches, service disruption, or complete system takeover. Organizations may face regulatory compliance violations, financial losses, and reputational damage if this vulnerability is exploited. The remote nature of the attack means that threat actors can exploit this vulnerability from anywhere on the internet, making traditional network security measures insufficient to prevent exploitation.
The vulnerability aligns with CWE-434, which describes the weakness of unrestricted upload of file with dangerous type, and maps to multiple ATT&CK techniques including T1190 for Exploit Public-Facing Application and T1059 for Command and Scripting Interpreter. Organizations should immediately implement mitigations including restricting file upload capabilities, implementing strict file type validation, and deploying web application firewalls to monitor and block malicious upload attempts. Additionally, the affected system should be updated to a patched version of mingSoft MCMS, and all unnecessary file upload functionality should be disabled until proper security controls are implemented. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other components of the system, as this represents a pattern of insecure file handling practices that may exist elsewhere in the application architecture.