A flaw in the automatic client-side encryption schema generation of the Mongoid ODM may cause values that an application declared for encryption to be written and stored as cleartext when more than one model is mapped onto the same storage location. No error or warning is raised. A party holding an ordinary read-only database account, with no access to the encryption key material, may then obtain those values in clear form.

A Ruby object-document mapper does not apply its automatic field-level encryption configuration to certain fields when the data model uses class inheritance. Values the application designated for encryption are written to the database in readable form without any error or warning. A database account holding only read access to the application's collections, and no access to the encryption key store, may obtain those values.