Migration risk is the security and operational exposure that can appear when data, accounts, or workflows move between platforms, storage models, or file formats. During a migration, content may be copied, transformed, re-permissioned, or left behind. That can create gaps in access control, retention, auditability, and version integrity.
In cyber security, migration risk matters because attackers often exploit transition periods. Misconfigured sharing links, stale permissions, incomplete transfers, and orphaned data can expose sensitive information or disrupt business processes. Defenders reduce the risk by inventorying content, testing conversions, validating ownership, checking retention rules, and confirming that old systems are safely decommissioned. Good migration planning treats the move itself as part of the security boundary, not just a technical housekeeping task.