Betas are not meant to be very secure. They have a lot of code that has not been tested yet. That’s part of the beta process. The security fixes will eventually be incorporated, but you will always be behind on the latest patches and there will be far more security holes that are unpatched in the betas or even the GM until October or November. Right now it is crunch culture to finish by September. Everything else will just have to wait. If security is your top concern, I recommend staying on iOS 26 for now.