Database
db={"vulns":[{"_id":1,"advisoryId":"44444"},{"_id":2,"advisoryId":"55555"},{"_id":3,"advisoryId":"66666"}],"tracker":[{"_id":1,"customerId":"12345","advisory":{advisoryId:"44444"}},{"_id":2,"customerId":"12345","advisory":{advisoryId:"55555"}},{"_id":3,"customerId":"12456","advisory":{advisoryId:"55555"}}]}
Query
db.vulns.find({"advisoryId":{$nin:["44444","55555"]}})