CVE-2026-1898 identifies an improper access control vulnerability within the LDAP User Sync component of WeKan, an open-source kanban board application widely used for project management and collaboration. The flaw resides in the file packages/wekan-ldap/server/syncUser.js and affects all versions up to 8.20. This vulnerability allows remote attackers to exploit insufficient access control checks, potentially enabling unauthorized manipulation of user synchronization processes between WeKan and LDAP directories. The attack vector is network-based, requiring no user interaction and only limited privileges, which lowers the barrier for exploitation. The vulnerability impacts confidentiality, integrity, and availability to a limited extent, as attackers could potentially access or modify user synchronization data or disrupt synchronization operations. The issue is resolved in version 8.21 by applying a patch that corrects the access control logic. No public exploits have been reported, but the nature of the vulnerability suggests that attackers could leverage it to gain unauthorized access or escalate privileges within WeKan deployments integrated with LDAP. Given WeKan's role in managing organizational workflows and sensitive project data, exploitation could lead to unauthorized data exposure or disruption of business processes.

For European organizations, the vulnerability poses a risk of unauthorized access or modification of user synchronization data between WeKan and LDAP directories, potentially leading to exposure of sensitive user information or disruption of authentication and authorization processes. This could affect confidentiality by leaking user data, integrity by allowing unauthorized changes to user sync configurations, and availability by disrupting synchronization services. Organizations relying on WeKan for project management and collaboration, especially those integrating with LDAP for centralized user management, may face operational disruptions and increased risk of insider threats or external attackers gaining footholds. The impact is more pronounced in sectors with strict data protection requirements such as finance, healthcare, and government, where unauthorized access could lead to regulatory non-compliance and reputational damage.

European organizations should immediately upgrade all affected WeKan instances to version 8.21 or later to apply the official patch addressing this vulnerability. Beyond patching, organizations should audit LDAP integration configurations to ensure least privilege principles are enforced and monitor synchronization logs for anomalous activities indicative of exploitation attempts. Implement network segmentation to restrict access to WeKan servers and LDAP services only to trusted hosts and users. Employ multi-factor authentication and robust access controls on administrative interfaces to reduce the risk of privilege escalation. Regularly review user permissions and conduct penetration testing focused on LDAP integration points. Additionally, maintain up-to-date backups of WeKan data and configurations to enable rapid recovery in case of compromise or disruption.