CVE-2025-11429 is a session management vulnerability identified in Red Hat's build of Keycloak version 26.2. The issue arises from a logic flaw where the system fails to immediately enforce the disabling of the 'Remember Me' feature at the realm level on existing user sessions. Specifically, sessions that were initiated while the 'Remember Me' option was active retain their extended session lifetime until they naturally expire, even after an administrator disables this setting. This occurs because the session expiration logic relies solely on a session-local 'remember-me' flag without revalidating the current realm-level configuration. Consequently, this flaw extends the window during which an attacker could hijack a session or maintain unauthorized persistent access, as sessions remain valid longer than intended. The vulnerability has a CVSS 3.1 base score of 5.4, indicating medium severity, with an attack vector of network, low attack complexity, requiring privileges but no user interaction, and impacts on confidentiality and integrity but not availability. No known exploits have been reported in the wild, and no patches or mitigations are explicitly linked in the provided data, suggesting the need for administrators to monitor updates closely. This vulnerability highlights the importance of robust session management and immediate enforcement of security configuration changes in identity and access management systems like Keycloak.

For European organizations, this vulnerability could lead to unauthorized prolonged access to sensitive systems and data managed via Keycloak, a widely used open-source identity and access management solution. The extended session lifetime increases the risk of session hijacking attacks, potentially allowing attackers to impersonate legitimate users for longer periods, compromising confidentiality and integrity of user data and organizational resources. This is particularly critical for sectors with stringent data protection requirements such as finance, healthcare, and government. The flaw may undermine recent security policy changes intended to reduce session duration, thereby weakening overall security posture. While availability is not directly impacted, the breach of confidentiality and integrity could lead to regulatory penalties under GDPR and damage to organizational reputation. The medium severity rating reflects a moderate but significant risk that requires timely attention to prevent exploitation.

Organizations should immediately audit their Keycloak session management configurations and identify active sessions created under the 'Remember Me' setting. Since existing sessions retain extended lifetimes, administrators should consider forcibly terminating all active sessions or implementing a manual session invalidation process to enforce the updated realm-level settings. Monitoring and logging of session activity should be enhanced to detect unusual session durations or access patterns. Applying any forthcoming patches from Red Hat promptly is critical once available. Additionally, organizations can implement compensating controls such as multi-factor authentication (MFA) to reduce the risk of session hijacking and enforce stricter network segmentation to limit exposure. Reviewing and tightening privilege assignments to reduce the number of users who can modify session settings will also help mitigate risk. Finally, educating users about session security and encouraging regular logout practices can reduce the window of opportunity for attackers.