CVE-2026-1898 in WeKan (SyncLDAPBleed)
Summary
by MITRE • 02/05/2026
A vulnerability was determined in WeKan up to 8.20. This affects an unknown part of the file packages/wekan-ldap/server/syncUser.js of the component LDAP User Sync. This manipulation causes improper access controls. It is possible to initiate the attack remotely. Upgrading to version 8.21 is able to mitigate this issue. Patch name: 146905a459106b5d00b4f09453a6554255e6965a. You should upgrade the affected component.
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Analysis
by VulDB Data Team • 02/05/2026
The vulnerability identified as CVE-2026-1898 represents a critical access control flaw within the WeKan collaborative platform's LDAP user synchronization functionality. This issue specifically resides in the file packages/wekan-ldap/server/syncUser.js which governs how user accounts are synchronized between WeKan and external LDAP directories. The flaw allows for improper access controls that could potentially enable unauthorized users to manipulate the LDAP synchronization process, thereby compromising the integrity of user authentication and authorization within the system. The vulnerability affects all versions of WeKan up to and including version 8.20, making it a significant concern for organizations relying on this platform for collaborative work management.
The technical nature of this vulnerability stems from insufficient validation and authorization checks within the LDAP user synchronization component. When the syncUser.js file processes user information from LDAP directories, it fails to properly verify the authenticity and permissions of the entities initiating the synchronization process. This weakness creates a pathway for malicious actors to exploit the system's trust model and potentially gain unauthorized access to user accounts or manipulate the synchronization process itself. The vulnerability's remote exploitability means that attackers do not require physical access to the system or local network privileges to initiate the attack, significantly expanding the potential attack surface and making it particularly dangerous for publicly accessible WeKan installations.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it could enable attackers to manipulate user permissions, escalate privileges, or potentially gain persistent access to the collaborative platform. Organizations using WeKan with LDAP integration may find their user authentication systems compromised, leading to potential data breaches or unauthorized modifications to collaborative workspaces. The vulnerability particularly affects environments where WeKan serves as a central collaboration tool and where LDAP integration is used for user management, making it a significant threat to enterprise security infrastructure. This flaw could also enable attackers to establish footholds within organizations by leveraging compromised user accounts or by creating backdoor access through manipulated synchronization processes.
The mitigation strategy for this vulnerability involves upgrading to WeKan version 8.21, which includes the patch identified by the commit hash 146905a459106b5d00b4f09453a6554255e6965a. This upgrade addresses the root cause by implementing proper access control checks within the LDAP synchronization process. Organizations should prioritize this upgrade as a critical security measure, especially in environments where WeKan is exposed to external networks or where LDAP integration is actively used for user management. Additionally, security teams should review their current LDAP integration configurations and monitor for any suspicious synchronization activities that might indicate exploitation attempts. The fix aligns with industry best practices for access control implementation and represents a corrective measure addressing potential CWE-284 (Improper Access Control) violations that could be leveraged in accordance with ATT&CK technique T1078 (Valid Accounts) and T1566 (Phishing).