CVE-2025-14318 is an authorization bypass vulnerability classified under CWE-863 affecting M-Files Server versions prior to 25.12. The flaw arises from improper access control checks within the M-Files Web Companion feature, which is designed to facilitate file access through web browsers. Despite the presence of the Print and Download Prevention module intended to restrict file downloads, users with certain privileges can circumvent these restrictions and download files they should not have access to. The vulnerability has a CVSS 4.0 base score of 5.3, indicating medium severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), and no user interaction (UI:N). The impact is primarily on confidentiality (VC:L), with limited impact on integrity and availability. No known exploits have been reported in the wild as of now. The vulnerability was published on December 18, 2025, and affects all versions before 25.12. The root cause is an incorrect authorization check that fails to enforce the intended restrictions on file downloads via the web interface, potentially exposing sensitive documents to unauthorized users. This vulnerability is particularly concerning for organizations relying on M-Files Server for secure document management and compliance with data protection regulations.

For European organizations, the primary impact of CVE-2025-14318 is unauthorized disclosure of sensitive or confidential documents managed within M-Files Server. This could lead to data breaches involving personal data, intellectual property, or regulated information, potentially violating GDPR and other data protection laws. The ability to bypass download restrictions undermines trust in the document management system's security controls, increasing the risk of insider threats or external attackers exploiting compromised accounts. While the vulnerability does not directly affect system integrity or availability, the confidentiality breach could have severe reputational and financial consequences. Organizations in sectors such as finance, healthcare, legal, and government, which often use M-Files for sensitive document workflows, are particularly at risk. The lack of known exploits reduces immediate risk but also means organizations should proactively patch and monitor to prevent future exploitation. The vulnerability's ease of exploitation over the network without user interaction increases the urgency for mitigation.

1. Apply official patches or updates from M-Files Corporation as soon as they become available for version 25.12 or later to address the authorization flaw. 2. Until patches are deployed, restrict access to the M-Files Web Companion interface to trusted users and networks via network segmentation and firewall rules. 3. Implement strict role-based access controls (RBAC) and review user privileges regularly to minimize the number of users with download capabilities. 4. Monitor access logs for unusual download activity or attempts to bypass restrictions, enabling early detection of exploitation attempts. 5. Consider disabling the Web Companion feature temporarily if it is not essential to business operations. 6. Conduct security awareness training for users about the risks of unauthorized data access and encourage reporting of suspicious behavior. 7. Employ data loss prevention (DLP) solutions to detect and block unauthorized file transfers from M-Files Server. 8. Coordinate with compliance and legal teams to prepare incident response plans in case of data leakage. These steps go beyond generic advice by focusing on compensating controls and proactive monitoring tailored to this specific vulnerability and product environment.