CVE-2025-64687 is a vulnerability classified under CWE-862 (Improper Access Control) found in JetBrains YouTrack versions before 2025.3.104432. The issue arises because the application does not adequately restrict access to modify the MCP (most likely a component or plugin management tool) tool logic, allowing users with limited privileges to alter its behavior. The vulnerability has a CVSS 3.1 base score of 5.4, indicating a medium severity level. The attack vector is network-based (AV:N), requiring low privileges (PR:L), no user interaction (UI:N), and affects confidentiality and integrity (C:L/I:L) but not availability (A:N). This means an authenticated user with some access rights can remotely exploit the flaw to modify internal logic, potentially leading to unauthorized changes in project tracking workflows or leakage of sensitive project data. No public exploits have been reported yet, and no patches are currently linked, but the vulnerability is officially published and should be addressed. The flaw could be leveraged in targeted attacks against organizations relying on YouTrack for project management, especially where internal controls are weak or user privilege management is lax.

For European organizations, the impact of CVE-2025-64687 can be significant in environments where YouTrack is used extensively for issue tracking, project management, and software development lifecycle management. Unauthorized modification of MCP tool logic could lead to integrity violations, such as tampering with project data, workflows, or issue statuses, potentially disrupting development processes and causing mistrust in project tracking data. Confidentiality could also be compromised if sensitive project information or user data is exposed through manipulated access controls. Although availability is not directly affected, the indirect consequences of corrupted project data or workflow manipulation could delay critical projects or compliance activities. Organizations in sectors with stringent regulatory requirements (e.g., finance, healthcare, government) may face compliance risks if unauthorized changes go undetected. The medium severity suggests a moderate risk, but the requirement for authenticated access limits exposure to insider threats or compromised accounts. However, given the widespread use of JetBrains products in Europe, the vulnerability could be exploited in targeted attacks against high-value software development environments.

1. Monitor JetBrains official channels closely for the release of the patched version 2025.3.104432 or later and apply updates immediately upon availability. 2. Conduct an internal audit of user privileges in YouTrack to ensure the principle of least privilege is enforced, minimizing the number of users with modification rights to MCP tool logic. 3. Implement strict access control policies and role-based access management within YouTrack to prevent unauthorized privilege escalation. 4. Enable and review detailed logging and monitoring of changes to MCP tool logic and related configurations to detect suspicious activities early. 5. Consider network segmentation and limiting access to YouTrack instances to trusted internal networks or VPNs to reduce exposure. 6. Educate administrators and users about the risks of privilege misuse and encourage prompt reporting of unusual system behavior. 7. If possible, perform penetration testing or vulnerability assessments focused on access control mechanisms within YouTrack to identify other potential weaknesses. 8. Maintain regular backups of YouTrack configurations and project data to enable recovery in case of tampering.