In the age of utility computing or cloud computing, Multi-tenancy has become popular and is acknowledged mainly as Software as a Service (SaaS) to the next level generations. Also, the specific application of Cloud computing even allows users, customers, and tenants to modify it reliably or robustly. Notwithstanding, it cannot be denied that the specific software allows customisation to its tenants and due to these errors increases and causes security risks. Also, it cannot be denied that there are various benefits of Multi-tenancy in a SaaS. Whereas various studies determined the challenges and threats of Multi-tenancy in a SaaS as well.