SearchUsersPermissions returns cross-org users

This vulnerability only affects Grafana stacks configured with multiple organizations; single-organization deployments are not impacted. In a multi-organization stack, a user who is an Org Admin of a single organization can call GET /api/access-control/users/permissions/search?actionPrefix=dashboards: and receive permission data belonging to other organizations. The disclosed data is limited to dashboard and folder identifiers (UIDs) and per-user permission/scope mappings (which user holds which access on which dashboard). Dashboard contents, panels, query results, datasource credentials, secrets, and personal data are not exposed. This is a limited cross-organization information disclosure affecting multi-org deployments only.