CVE-2026-25108 is an OS command injection vulnerability identified in Soliton Systems K.K.'s FileZen file transfer and management software, specifically affecting versions 5.0.0 through 5.0.10. The vulnerability arises when the Antivirus Check Option is enabled, which improperly neutralizes special elements in user-supplied input within HTTP requests. This improper input sanitization allows an authenticated user to craft HTTP requests that execute arbitrary operating system commands on the server hosting FileZen. The vulnerability has a CVSS 3.0 base score of 8.8, indicating high severity, with an attack vector of network (remote), low attack complexity, requiring privileges (logged-in user), no user interaction, and impacts confidentiality, integrity, and availability. Exploitation could lead to full system compromise, data theft, data manipulation, or denial of service. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the ease of exploitation by authenticated users and the critical nature of the affected systems. FileZen is widely used in enterprise environments for secure file transfer, making this vulnerability particularly concerning for organizations relying on it for sensitive data handling. The vulnerability was published on February 13, 2026, with no patches or mitigations officially released at the time of reporting, emphasizing the need for immediate defensive measures.

The impact of CVE-2026-25108 is severe for organizations using vulnerable versions of FileZen. Exploitation allows an authenticated user to execute arbitrary OS commands, potentially leading to full system compromise. This can result in unauthorized data access, data exfiltration, data corruption, or complete service disruption. Given FileZen's role in secure file transfer and management, attackers could manipulate or steal sensitive files, disrupt business operations, or use the compromised system as a foothold for lateral movement within the network. The vulnerability affects confidentiality, integrity, and availability, making it a critical risk. Organizations in sectors such as finance, healthcare, government, and technology that handle sensitive data are particularly at risk. The lack of known exploits in the wild currently provides a window for proactive mitigation, but the ease of exploitation once an attacker gains authenticated access elevates the threat level significantly.

1. Immediately restrict access to the FileZen management interface to trusted administrators only, using network segmentation and firewall rules. 2. Disable the Antivirus Check Option in FileZen if it is not essential for operations until a patch is available. 3. Monitor HTTP request logs for unusual or suspicious patterns indicative of command injection attempts, such as unexpected special characters or command syntax. 4. Implement strong authentication controls and limit user privileges to reduce the risk of exploitation by unauthorized or low-privilege users. 5. Apply application-layer web application firewalls (WAFs) with custom rules to detect and block OS command injection payloads targeting FileZen endpoints. 6. Regularly check for and apply official patches or updates from Soliton Systems K.K. as soon as they are released. 7. Conduct internal security assessments and penetration tests focusing on FileZen to identify potential exploitation attempts. 8. Educate administrators and users about the risks of this vulnerability and the importance of secure configuration and monitoring.