An object-document mapper (ODM) is a library layer that lets application code work with database documents as ordinary objects. Instead of manually converting JSON-like records to and from program data structures, the ODM handles that translation for the developer. Mongoid is a common example in Ruby applications.
In cyber security, an ODM sits on the trust boundary between user input and database operations. If it mishandles parsing, validation, or query construction, attackers may bypass controls, inject unexpected fields, alter records, or trigger denial of service. Because ODMs are embedded in application code, flaws can affect confidentiality, integrity, and availability even when the database server itself is configured correctly. Defenders should keep ODM packages patched, review how models validate input, and test that dangerous fields and queries are blocked before they reach the database.