If you search the internet, you may find files named "PS4 Update Downgrader" or similar. Exercise extreme caution.
Most of these files are:
Exploit developers (like TheFlow, SpecterDev) work on newer firmwares. Historically, jailbreaks have appeared for 6.72, 7.55, and 9.00. Firmware 10.01 and 11.00 may see public exploits in the future. Patience costs $0. downgrade tool ps4