DataEase before 2.10.26 contains multiple access control defects in the sharing link module. Tickets are not bound to the target share UUID, so a valid ticket issued for one share can be reused against another (ShareTicketManage.validateTicket / POST /de2api/share/proxyInfo). The POST /de2api/share/validate endpoint issues a LinkToken after password verification without requiring a ticket, bypassing the 'ticket mandatory' policy. Additionally, the ticket create and delete endpoints (POST /de2api/ticket/saveTicket, POST /de2api/ticket/delTicket) lack share-ownership checks, allowing an authenticated user who knows another user's ticket to modify, rebind, or delete it (denial of service), and GET /de2api/share/queryRelationByUserId/{uid} allows authenticated users to enumerate other users' share mappings.