An exploit for the PS4's firmware 7.55 was revealed today by hacking scene member TheFlow. However, it was actually reported back in June 2020 and disclosed only today as TheFlow worked with Sony's HackerOne bounty program to patch this vulnerability. The reported exploit was marked as resolved in October. TheFlow also did similar disclosures with previous exploits he found and helped fix.
The HackerOne page notes that this vulnerability can cause a "fully chained remote attack" when used with a WebKit exploit, steal/manipulate user data and even dump and run pirated games. As such, it could be used together with the Webkit exploit from last December to jailbreak PS4 systems on firmware 7.55. However, no relevant files have been made publicly available regarding the FW 7.55 exploit with today's disclosure.