I think a vanilla project will have fewer vulnerabilities, not more. Most of the vulnerabilities in frameworks are in the very complicated build tooling or deeply nested dependencies. A vanilla project doesn’t have that, so there are entire classes of vulnerabilities that don’t occur there. Vanilla does come with a higher risk of XSS, but basically all you need is a templating function that does XSS defense like lit-html and you’re good to go.
I suppose that you are not writing your db driver from scratch and you are using a driver that was at least written in the last 10 years, so it will support for sure prepared statements and you will use it, that means no possibility of SQL injections.
