CVE-2026-1894 is an improper authorization vulnerability identified in the WeKan open-source kanban board application, specifically in the REST API component handling checklist items (file models/checklistItems.js). The flaw allows an attacker to manipulate parameters such as item.cardId, item.checklistId, or card.boardId to bypass authorization controls. This improper validation means that an attacker with network access can remotely perform unauthorized operations on checklist items, potentially accessing or modifying data they should not have permission to. The vulnerability affects all WeKan versions from 8.0 through 8.20. The issue does not require user interaction or elevated privileges but does require some level of access to the API (likely authenticated with limited privileges). The CVSS 4.0 score of 5.3 reflects a medium severity, considering the network attack vector, low complexity, no user interaction, and limited impact on confidentiality, integrity, and availability. The vulnerability was patched in version 8.21 with a specific code fix (commit 251d49eea94834cf351bb395808f4a56fb4dbb44). No known exploits have been reported in the wild, but the potential for unauthorized data manipulation or access makes timely patching critical.

For European organizations, this vulnerability poses a risk of unauthorized access and modification of project management data stored in WeKan. This could lead to leakage of sensitive business information, unauthorized changes to task statuses or checklists, and potential disruption of collaborative workflows. While the impact on confidentiality, integrity, and availability is rated low, the unauthorized access could undermine trust in project management processes and expose organizations to compliance risks, especially under GDPR if personal data is involved. Organizations relying heavily on WeKan for internal or cross-border collaboration may face operational inefficiencies or reputational damage if exploited. The remote exploitability increases risk, particularly for organizations exposing WeKan APIs to the internet or insufficiently segmented internal networks.

European organizations should immediately upgrade all affected WeKan instances to version 8.21 or later to apply the official patch. Additionally, organizations should audit API access controls and ensure that only authenticated and authorized users can access sensitive REST API endpoints. Implement network segmentation and firewall rules to restrict access to WeKan services, limiting exposure to trusted internal networks or VPNs. Enable detailed logging and monitoring of API usage to detect anomalous access patterns indicative of exploitation attempts. Conduct regular security reviews of custom integrations or plugins that interact with the checklistItems API to ensure they do not introduce further authorization weaknesses. Finally, educate administrators and users about the importance of timely patching and secure configuration management for collaboration tools.