I use Lubuntu and their versions of Java and flash etc and so far I have been lucky and have had none of the security issues previously associated with Windows, although Windows 10 is supposed to be extremely secure using defender/malware etc.
I use freeBSD myself.
Flash will bypass any proxy or VPN you are using and report your actual IP address when quesioned. I believe the same is true with Java applets, I would have to double check the Java specification to confirm this however.