As you probably know, firmwares 6.37 and 6.38 allow you to play “regular” homebrews through HBL, as well as “signed” homebrews, including some backups with the fake_np tool. But these two firmwares cannot run Custom Firmwares or HENs, which offer a much more “integrated” experience, as well as the support for custom themes and plugins. In order to run a CFW, a Kernel exploit is required, and the Kernel exploit that is used on firmwares 6.20 and 6.35 has been patched by Sony in firmware 6.37.
However, Developer Total_Noob announced via a video on his youtube Channel that he found a new Kernel exploit on firmware 6.38.
The video doesn’t show much, and a user-mode fake homebrew could do the same, but given the source I’m inclined to say that this is legit
Total_Noob states in his video that he has no current plan to release anything for now, so let’s wait a little bit
Feel free to discuss this breakthrough in the dedicated thread on /talk