In late December, hackers announced they had discovered a kernel exploit for PS4 firmware version 4.05, allowing them to release a mod software called PS4HEN. This software enables homebrew applications and the loading of backup game files. As proof, you can check out YouTuber Andrew2007 running a test homebrew application on his PS4.
While in the midst of getting deep into the PS4, it was discovered that the PS4 had a PS2 emulator hidden in its firmware. As a result, a tool has been developed for PS4HEN that allows you to run backups of PS2 games on the PS4. Games like Klonoa 2 and Shinobi have been proven to work on jailbroken PS4s.
You can only jailbreak your PS4 only if it really has a very old firmware on it. Recent updated PS4s can't be broken, yet.
While in the midst of getting deep into the PS4, it was discovered that the PS4 had a PS2 emulator hidden in its firmware. As a result, a tool has been developed for PS4HEN that allows you to run backups of PS2 games on the PS4. Games like Klonoa 2 and Shinobi have been proven to work on jailbroken PS4s.
You can only jailbreak your PS4 only if it really has a very old firmware on it. Recent updated PS4s can't be broken, yet.