CVE-2025-53900 is a vulnerability classified under CWE-267 (Privilege Defined With Unsafe Actions) affecting Kiteworks Managed File Transfer (MFT) software versions prior to 9.1.0. Kiteworks MFT is designed to orchestrate secure end-to-end file transfer workflows, often used in enterprise environments to manage sensitive data exchanges. The vulnerability arises from an improper definition and enforcement of roles and permissions related to managing Connections within the platform. Specifically, authorized users with certain roles can exploit the flawed permission model to escalate their privileges beyond intended limits, potentially gaining administrative capabilities or unauthorized control over file transfer configurations. The CVSS v3.1 base score is 6.5 (medium), reflecting that the attack vector is network-based (AV:N), requires low attack complexity (AC:L), but does require privileges (PR:L) and no user interaction (UI:N). The impact is primarily on integrity (I:H), with no direct confidentiality or availability impact. The scope is unchanged (S:U), meaning the vulnerability affects only the vulnerable component. Although no exploits have been reported in the wild, the vulnerability poses a risk to organizations relying on Kiteworks MFT for secure data workflows. The issue was publicly disclosed on November 29, 2025, and patched in version 9.1.0. Organizations running affected versions should upgrade promptly to prevent potential privilege escalation attacks that could compromise the integrity of file transfer operations.

For European organizations, the primary impact of CVE-2025-53900 is the risk of unauthorized privilege escalation within Kiteworks MFT environments, which can lead to unauthorized modification or disruption of critical file transfer workflows. This can undermine data integrity, potentially allowing malicious actors or insider threats to alter, reroute, or manipulate sensitive data transfers without detection. Given the role of MFT solutions in regulated industries such as finance, healthcare, and government, such integrity breaches could result in compliance violations, data mishandling, and operational disruptions. The absence of confidentiality and availability impacts limits the scope to integrity, but the potential for unauthorized administrative control elevates the risk profile. European entities with stringent data protection regulations (e.g., GDPR) may face legal and reputational consequences if such vulnerabilities are exploited. Additionally, the vulnerability could be leveraged as a foothold for further lateral movement within networks, increasing overall organizational risk.

1. Immediate upgrade of Kiteworks MFT installations to version 9.1.0 or later to apply the official patch addressing the privilege escalation vulnerability. 2. Conduct a thorough audit of user roles and permissions within Kiteworks MFT, ensuring the principle of least privilege is enforced, especially for users managing Connections. 3. Implement strict access controls and segmentation for administrative functions related to file transfer workflows to limit exposure. 4. Monitor logs and alerts for unusual privilege changes or access patterns indicative of exploitation attempts. 5. Employ multi-factor authentication (MFA) for all users with elevated privileges to reduce risk of credential compromise. 6. Regularly review and update security policies governing file transfer operations to incorporate lessons learned from this vulnerability. 7. Consider network-level restrictions to limit access to Kiteworks MFT management interfaces only to trusted administrative hosts. 8. Train administrators and security teams on recognizing and responding to privilege escalation indicators within the platform.