CVE-2025-65780 is a critical authorization vulnerability discovered in Wekan, an open-source kanban board system widely used for task and project management. The issue exists in all versions up to 18.15 and was resolved in version 18.16. The root cause is the absence of proper server-side authorization checks when authenticated users attempt to update their user documents. Normally, users should only be able to modify limited profile fields; however, due to this flaw, they can alter the entire user document, including sensitive attributes such as organizational affiliations (orgs/teams) and the loginDisabled flag. This unauthorized modification capability allows attackers to escalate privileges by assigning themselves to other teams or organizations, or by re-enabling disabled accounts, thereby gaining unauthorized access to resources and data across different organizational boundaries. The vulnerability is remotely exploitable over the network (AV:N), requires low attack complexity (AC:L), and only needs privileges of an authenticated user (PR:L) without any user interaction (UI:N). The impact spans confidentiality, integrity, and availability (C:H/I:H/A:H), as attackers can access sensitive data, manipulate user roles, and potentially disrupt operations. Although no exploits are currently known in the wild, the severity and ease of exploitation make this a significant threat. The CWE classification is CWE-284 (Improper Access Control), highlighting the failure to enforce proper authorization. Organizations relying on Wekan for collaboration and project tracking should prioritize upgrading to version 18.16 or later to remediate this vulnerability.

For European organizations, the impact of CVE-2025-65780 can be substantial, particularly for those using Wekan in environments with multiple teams or organizational units. Unauthorized privilege escalation can lead to data breaches, exposing sensitive project information and internal communications. Attackers could manipulate team memberships to access confidential tasks or documents, undermining confidentiality. Integrity is compromised as unauthorized users can alter project data or user statuses, potentially disrupting workflows or causing operational confusion. Availability may also be affected if attackers disable legitimate user accounts or manipulate access controls, leading to denial of service for legitimate users. Given the collaborative nature of Wekan, such breaches could cascade into broader organizational risks, including regulatory compliance violations under GDPR if personal or sensitive data is exposed. The risk is amplified in sectors with strict data protection requirements such as finance, healthcare, and government institutions across Europe.

To mitigate this vulnerability, European organizations should immediately upgrade Wekan installations to version 18.16 or later, where the authorization checks have been properly implemented. Until patching is complete, restrict access to Wekan to trusted users only and review user privileges to ensure minimal necessary access. Implement network-level controls such as VPNs or IP whitelisting to limit exposure. Conduct thorough audits of user accounts and organizational memberships to detect any unauthorized changes. Employ monitoring and alerting for unusual user document modifications or privilege escalations. Additionally, enforce strong authentication mechanisms, such as multi-factor authentication (MFA), to reduce the risk of compromised credentials. Regularly review and update access control policies to ensure they align with the principle of least privilege. Finally, educate users about the importance of reporting suspicious activity promptly.