CVE-2025-57766 is a vulnerability identified in the open-source privacy engineering platform Ethyca Fides, specifically affecting versions prior to 2.69.1. The vulnerability is classified under CWE-613, which pertains to insufficient session expiration. The core issue lies in the handling of active user sessions during an administrative user password change within the Fides admin UI. When an admin changes a user's password, the system fails to invalidate existing active sessions associated with that user. This flaw creates a security gap where an attacker who has previously obtained valid session tokens—potentially through other attack vectors such as cross-site scripting (XSS)—can continue to access the system even after the password has been reset. This persistence of session tokens undermines the security benefits of password changes, which are typically intended to revoke unauthorized access. Importantly, this vulnerability is not directly exploitable on its own; it requires a prerequisite condition where an attacker has already acquired valid session tokens through other means. The vulnerability was addressed and fixed in version 2.69.1 of Fides. There are no known workarounds available, emphasizing the importance of upgrading to the patched version. The CVSS 4.0 score assigned is 1.7, indicating a low severity level. The vector details show that the attack vector is network-based but requires high attack complexity, no privileges, no user interaction, and results in low impact on integrity with no impact on confidentiality or availability. No known exploits are currently reported in the wild.

For European organizations utilizing Ethyca Fides, particularly those managing sensitive privacy engineering workflows and compliance data, this vulnerability could allow attackers who have already compromised session tokens to maintain unauthorized access even after password resets. This persistence could lead to prolonged unauthorized data access or manipulation, undermining trust in privacy controls and potentially violating data protection regulations such as the GDPR. While the direct impact is limited due to the prerequisite of session token compromise, the failure to invalidate sessions weakens the overall security posture and incident response effectiveness. Organizations relying on Fides for privacy engineering may face increased risk of data exposure or manipulation if attackers chain this vulnerability with other exploits. The low CVSS score reflects limited standalone risk, but the potential for session persistence could be critical in targeted attacks against high-value systems or data. Given the importance of privacy compliance in Europe, any unauthorized access to privacy engineering tools can have regulatory and reputational consequences.

The primary and most effective mitigation is to upgrade Ethyca Fides to version 2.69.1 or later, where the session invalidation issue has been resolved. Organizations should implement strict session management policies, including enforcing session expiration and revocation upon password changes or other critical account modifications. Monitoring and logging of session activities should be enhanced to detect unusual session persistence or reuse. Additionally, organizations should conduct thorough security assessments to identify and remediate any prerequisite vulnerabilities that could allow attackers to obtain session tokens, such as XSS or other injection flaws. Employing multi-factor authentication (MFA) can reduce the risk of session token compromise. Network segmentation and limiting administrative UI access to trusted networks or VPNs can further reduce exposure. Since no workarounds exist, patching remains the only reliable defense. Regularly reviewing and updating incident response plans to include session token compromise scenarios will improve readiness.