Zakura Node Hits Four-Hour Sync as Zcash Preps July 28 Ironwood Upgrade
Zcash developers are sealing off a shielded pool that carried a critical bug, and a new node built for speed is already backing the fix. Key TakeawaysIronwood (NU6.3) seals Zcashs old Orchard pool at block 3,428,143 on July 28.Taylor Hornbys May bug find pushed ZEC lower before it stabilized above $500.Sean Bowe and Dev Ojhas Zakura node syncs Zcash 5 times faster than Zebra. The Ironwood hard fork, known as NU6.3, activates around July 28, 2026, at block height 3,428,143. It closes a soundness flaw in the Orchard shielded pool and opens a new pool built on corrected code. Alongside it, a fast new node called Zakura is already live, giving operators a faster way to run the network. A Bug Nobody Could See Security researcher Taylor Hornby, working with Shielded Labs, found the flaw in late May 2026. The bug sat inside Orchard‘s cryptographic circuits. In theory, it lets someone mint counterfeit ZEC inside the shielded pool without leaving a trace. Zcash’s privacy design, the same feature that protects users, also blocks outside observers from checking whether anyone has exploited it. Developers moved fast. A soft fork shut down the Orchard pool temporarily. A hard fork, NU6.2, patched the immediate danger. ZECs price dropped