CVE-2026-1894 is an improper authorization vulnerability discovered in the WeKan open-source kanban board application, affecting all versions up to 8.20. The vulnerability exists in the REST API, specifically within the models/checklistItems.js file. Attackers can manipulate key parameters—item.cardId, item.checklistId, and card.boardId—to bypass authorization checks improperly implemented in the API. This allows an attacker with limited privileges to perform unauthorized actions on checklist items or cards belonging to other users or boards. The flaw does not require user interaction and can be exploited remotely over the network. The vulnerability arises from insufficient validation of ownership or access rights when processing these identifiers, leading to unauthorized access or modification of data. The issue is resolved in version 8.21 by correcting the authorization logic. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no user interaction (UI:N), and privileges required are low (PR:L). The impact on confidentiality, integrity, and availability is limited but present (VC:L, VI:L, VA:L). No public exploits have been reported yet, but the vulnerability is significant for organizations relying on WeKan for task and project management.

The vulnerability allows attackers with low privileges to access or modify checklist items and cards they should not have access to, potentially leading to unauthorized disclosure of sensitive project information, unauthorized changes to task statuses, or disruption of project workflows. This can undermine data integrity and confidentiality within teams using WeKan, especially in environments where sensitive or proprietary information is managed. Since WeKan is often deployed in enterprise, educational, and governmental contexts for collaborative project management, exploitation could lead to insider threat scenarios or lateral movement within networks. The remote exploitability and lack of user interaction make it easier for attackers to leverage this flaw at scale. While the impact is moderate, organizations with strict data governance or compliance requirements may face regulatory or reputational risks if unauthorized access occurs.

The primary mitigation is to upgrade WeKan installations to version 8.21 or later, where the authorization logic has been fixed. Until upgrade is possible, organizations should restrict network access to the WeKan REST API to trusted users and networks only, using firewalls or VPNs. Implement strict role-based access controls and monitor API usage logs for unusual access patterns involving checklist items or cards. Conduct regular audits of user permissions to ensure least privilege principles are enforced. Additionally, consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious parameter manipulations targeting item.cardId, item.checklistId, or card.boardId. Educate administrators and users about the importance of timely patching and monitoring for anomalous activity. Finally, maintain backups of critical project data to enable recovery in case of unauthorized modifications.