CVE-2025-57766 is a security 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 fact that when an administrator changes a user's password through the Fides admin UI, the system does not invalidate existing active user sessions. This means that any session tokens that were previously issued remain valid even after the password reset. Consequently, if an attacker has already obtained valid session tokens—potentially through other attack vectors such as cross-site scripting (XSS)—they can maintain unauthorized access to the user account despite the password change. This vulnerability does not allow direct exploitation on its own; it requires a prerequisite vulnerability or attack vector to first acquire valid session tokens. The lack of session invalidation after password changes creates a chaining opportunity for attackers to persist in a compromised environment. The issue 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 v4.0 base score is 1.7, indicating a low severity level, primarily because exploitation requires prior access to valid session tokens and no direct remote exploitation is possible without additional vulnerabilities. The vulnerability impacts confidentiality by allowing unauthorized session persistence, but does not affect integrity or availability directly. The attack complexity is high due to the prerequisite conditions, and no user interaction or privileges are required once the session token is obtained.

For European organizations using Ethyca Fides, this vulnerability poses a risk primarily in environments where multiple vulnerabilities or attack vectors exist. Since Fides is a privacy engineering platform, it is likely used by organizations handling sensitive personal data to ensure compliance with data protection regulations such as GDPR. Persistent unauthorized access through stolen session tokens could lead to unauthorized data access or manipulation, potentially resulting in privacy breaches and regulatory non-compliance. Although the vulnerability itself is low severity, it can facilitate prolonged unauthorized access if combined with other weaknesses, increasing the risk of data exfiltration or insider threats. The inability to invalidate sessions after password changes undermines standard security practices and incident response measures, potentially delaying detection and remediation of compromised accounts. This is particularly critical for European organizations that must maintain strict audit trails and data protection controls. The lack of known workarounds means organizations must prioritize patching to mitigate risk effectively.

1. Immediate upgrade to Ethyca Fides version 2.69.1 or later to ensure the vulnerability is patched. 2. Implement strict session management policies, including limiting session lifetimes and enforcing session expiration on password changes at the application or infrastructure level if possible. 3. Conduct thorough security assessments to identify and remediate any prerequisite vulnerabilities (e.g., XSS) that could allow attackers to obtain session tokens. 4. Employ multi-factor authentication (MFA) to reduce the risk of session token misuse. 5. Monitor active sessions and implement anomaly detection to identify unusual session activity indicative of token theft or misuse. 6. Educate administrators and users on the importance of logging out from sessions after password changes and encourage regular session invalidation practices. 7. Use web application firewalls (WAFs) and security tools to detect and block attempts to exploit related vulnerabilities. 8. Maintain comprehensive logging and auditing to detect suspicious session persistence and respond promptly.