Breaking News: 2.60 Firmware Exploit Found - Kernel Access!
A developer known as hitchhikr of "hitchhikr SoftWorks" and coder companion Neural have come out with a Proof of Concept of a 2.50/2.60 Firmware Exploit! Once implemented and fine tuned for "normal user" use, this will bring 2.50 and 2.60 Firmware up to the same homebrew capability that 1.50 PSP owners enjoy with FULL kernel mode access - although Grand Theft Auto: Liberty City Stories will still be required, just like with eLoader.
Speaking of eLoader, Fanjita is already working with hitchhikr on incorporating this new exploit into an easily executable means via eLoader. After a brief chat with Fanjita, he's told us that you can expect some generic application for developers to hopefully be released in the next 24 hours. It will take a bit longer before something useable for non-devs will be released.
The exploit takes advantage of an added security check in 2.50/2.60 Firmware for sceKernelLoadExec, which is responsible for loading EBOOTs, but Sony also accidentally added an overflow bug, which means this exploit will not work with 2.0 and 2.01 Firmware.
But don't start upgrading those PSP's yet until a viable means of implementation is released! Also, this breakthrough does not open up the possibility of a downgrader due to the protection in the IPL in 2.50+ firmware. Although speculation has already begun that this will open the door to the decrypting of 2.70+ Firmware, allowing it to be emulated a la Devhook.