CVE-2025-56643 identifies a critical security vulnerability in Requarks Wiki.js version 2.5.307 related to improper handling of JSON Web Tokens (JWTs) during user logout. Specifically, the system fails to revoke or invalidate active JWT tokens when a user logs out, meaning that tokens issued prior to logout remain valid and can be reused to access the system. This issue stems from flaws in the authentication resolver logic, affecting both the GraphQL API endpoint and the logout mechanism. JWTs are commonly used for stateless authentication, and their security depends on timely invalidation upon session termination. The failure to revoke tokens compromises session integrity, allowing an attacker who has obtained a token—through theft, interception, or other means—to continue accessing the system with the privileges of the logged-out user. The vulnerability does not require any authentication or user interaction to exploit, and the attack vector is network-based. The CVSS v3.1 score of 9.1 reflects the critical nature of this flaw, with high impact on confidentiality and integrity but no direct impact on availability. Although no known exploits have been reported in the wild, the vulnerability presents a significant risk to organizations relying on Wiki.js for knowledge management, especially where sensitive or regulated information is stored. The CWE-613 classification highlights the issue as improper session expiration or invalidation, a common and serious security weakness in web applications.

For European organizations, the impact of CVE-2025-56643 can be severe. Unauthorized reuse of JWT tokens can lead to unauthorized access to sensitive corporate knowledge bases, intellectual property, or internal documentation. This could facilitate data breaches, insider threat activities, or lateral movement within networks. Organizations in regulated sectors such as finance, healthcare, and government are particularly vulnerable due to strict data protection requirements under GDPR and other regulations. The persistence of valid tokens after logout undermines trust in session management and can lead to compliance violations if unauthorized access results in data leakage. Additionally, Wiki.js is often used as a collaborative platform, so compromised accounts could allow attackers to alter or delete critical documentation, impacting operational integrity. The lack of availability impact means systems remain operational, potentially masking the presence of an ongoing breach. European entities with remote or hybrid workforces relying on web-based collaboration tools are at increased risk due to the network-exploitable nature of the vulnerability.

To mitigate CVE-2025-56643, organizations should prioritize upgrading Wiki.js to a version where the vulnerability is patched once available. In the interim, administrators can implement the following specific measures: 1) Introduce server-side token revocation lists or blacklists to invalidate JWTs upon logout or manual session termination. 2) Reduce JWT token lifetime to minimize the window of exposure if tokens are compromised. 3) Implement additional session management controls such as rotating tokens on sensitive operations and enforcing multi-factor authentication (MFA) to reduce the risk of token theft exploitation. 4) Monitor authentication logs and GraphQL API usage for anomalous token reuse patterns indicative of session hijacking. 5) Restrict access to the Wiki.js instance via network segmentation and VPNs to limit exposure. 6) Educate users on secure logout practices and the risks of token reuse. 7) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious JWT usage. These steps go beyond generic advice by focusing on compensating controls that address the core issue of token invalidation and session integrity.