Today a non leaked before 4.25 OFW for DEX console have been leaked by a new team called Mate Team.
It had been tested and verified by a DemonHades and Elotrolado members.
Also to note: its the last DEX firmware that can be installed to a converted consoles a.k.a CEX2DEX consoles, since a brick reports have been reported about upgrading a converted DEX consoles to a non leaked also 4.30 OFW for DEX.
BTW: Sony had implemented new security checks in 4.30 DEX OFW to check some values in eEID5, so since this part is not converted using leaked CEX2DEX methods then its easly find the non real DEX console and brick it.
Download it here: DEX 4.25 FW
Mirror: PS3 DEX Firmware 4.25 Mirror by PS3SceneFiles
NEWS SOURCE: DemonHades