PHP Security Concerns in Core Banking Solution

Hi All,
I am in the process to design and develop a core banking solution using PHP as primary language and followed by other technical framework and jargon.

My intended system will be available for backoffice set of users and as well as e-Banking for the customers over web. Two different systems.

I went through many of blogs on the PHP. Many have stated there is security concerns in PHP and understand PHP next version is majorly focused in security part.

Appreciate if someone can guide on this. Thank you.