CVE-2025-53896 is a vulnerability identified in the Kiteworks Managed File Transfer (MFT) platform, specifically affecting versions prior to 9.1.0. The root cause is insufficient session expiration (CWE-613), where under certain conditions, user sessions do not properly time out after inactivity. This flaw can lead to sessions remaining active indefinitely, increasing the risk that an attacker with access to a session token or a logged-in workstation can continue to operate under the authenticated user's privileges without reauthentication. The vulnerability requires local access with low privileges (AV:L/PR:L) but does not require user interaction (UI:N). The CVSS 3.1 base score is 7.1, indicating a high severity due to the high impact on confidentiality and integrity (C:H/I:H/A:N). The vulnerability does not affect availability. The flaw is particularly critical in environments where sensitive data is transferred and session management is a key security control. Kiteworks MFT orchestrates end-to-end file transfer workflows, often used in regulated industries and enterprises requiring secure data exchange. The vendor has addressed this issue in version 9.1.0 by correcting session timeout handling to ensure inactive sessions expire as expected. No public exploits or active exploitation have been reported to date, but the risk remains significant due to the potential for session hijacking or unauthorized prolonged access. Organizations using affected versions should prioritize patching to prevent exploitation.

For European organizations, the impact of this vulnerability is substantial, especially for those in sectors handling sensitive or regulated data such as finance, healthcare, legal, and government. Prolonged active sessions can lead to unauthorized data access, data leakage, or manipulation without detection, undermining confidentiality and integrity. Attackers could exploit this to maintain persistent access, bypassing session reauthentication controls. This risk is heightened in shared or public work environments where unattended sessions could be hijacked. The vulnerability could also facilitate insider threats or lateral movement within networks. Given the critical role of Kiteworks MFT in secure file transfer workflows, exploitation could disrupt business operations or lead to compliance violations under GDPR and other data protection regulations. The absence of known exploits reduces immediate risk but does not eliminate the threat, making proactive patching essential.

European organizations should immediately upgrade Kiteworks MFT to version 9.1.0 or later to apply the official patch addressing the session expiration flaw. Until patching is complete, implement compensating controls such as enforcing strict session timeout policies at the network or application gateway level, and monitor active sessions for unusual duration or activity. Employ multi-factor authentication (MFA) to reduce risk from compromised sessions. Limit local user privileges and restrict access to systems running Kiteworks MFT to trusted personnel only. Conduct regular audits of session management logs to detect anomalies. Educate users about the risks of leaving sessions unattended and enforce workstation lock policies. Additionally, segment networks to reduce the impact of potential session hijacking and deploy endpoint detection and response (EDR) tools to identify suspicious session-related activities. Maintain up-to-date incident response plans to quickly address any detected exploitation attempts.