When modifying a model item in the Yancy Editor (e.g 'user'), that has a field of type 'password', if you change any field OTHER than the password field (e.g 'email' or something), then submitting the form will cause the password type field to be re-hashed and persisted to the db - thereby changing the password unintentionally. Everything works fine if you send the password field (be it changed or unchanged) in plain-text so that the backend doesn't "rehash the hash".