CageFS is a virtualized filesystem and account isolation layer used in shared hosting. It gives each user a separate view of the system, hiding other users’ files, processes, and many sensitive paths. This helps prevent one compromised website account from freely reading or modifying data that belongs to another tenant on the same server.
In cyber security, CageFS matters because shared hosting is a multi-tenant environment: one weak account should not become everyone’s problem. Defenders use it to reduce cross-account impact, limit lateral movement, and make privilege abuse harder after an initial compromise. Attackers, however, may try to bypass or outgrow these controls by exploiting vulnerable server software, misconfigurations, or a privilege-escalation flaw that reaches the host itself. CageFS improves containment, but it does not replace patching, hardening, and least-privilege design.