Multi-tenant hosting is a server setup where one machine supports multiple customer sites, accounts, or applications at the same time. Each tenant shares the same underlying hardware and often the same management stack, while being logically separated from the others.
This model is common in shared hosting and managed server environments because it is efficient and easy to scale. In cyber security, however, it raises the stakes of any flaw in a shared component: if an attacker gains elevated access to the host, they may be able to reach data, settings, or backups belonging to other tenants. Defenders reduce this risk by enforcing strong isolation, limiting administrative access, patching control-panel and backup tools quickly, and monitoring for cross-account abuse or unexpected restore activity.