CVE-2026-55547

Name of the Vulnerable Software and Affected Versions Yamcs versions prior to 5.12.8 Yamcs versions prior to 5.13.2

Description Yamcs contains a broken function level authorization issue where certain IAM API endpoints omit necessary security checks. Any authenticated user, regardless of their assigned permissions, can enumerate the complete list of system privileges and configured role mappings. This disclosure of security configuration provides a roadmap that can support targeted privilege-escalation attempts.

The issue resides in the IamApi.java file within the following endpoints:

These endpoints fail to verify the SystemPrivilege.ControlAccess privilege, allowing low-privilege accounts to retrieve sensitive metadata about administrator-level capabilities.

Recommendations Update to version 5.12.8 or 5.13.2. As a temporary mitigation, restrict network access to the 'GET /api/roles', 'GET /api/roles/{name}', and 'GET /api/privileges' endpoints to only trusted administrative users.