Meh, not really. The risk with making it publicly available is that a nation state or leet hacker types can comb over it and find exploits or know what libraries/etc you are using so when a zero day pops up they can target you directly. Whereas without direct access to th source code they’d have to do their own enumeration and surveillance.

There is some security through obscurity.

Also, just want to point out: being open source doesn’t mean it’s more or less secure. There is plenty of vulnerable open source code out their.