TL;DR:
- Ironwood, Zcash’s network upgrade, could be delayed because wallets, exchanges and mining pools need more time to prepare.
- The issue stems from its overlap with the migration from zcashd to the Z3 stack, which includes Zebra, Zaino and Zallet, still under development.
- Zooko Wilcox confirmed that security reviews found no additional critical bugs, though the activation still has no definitive date.
The Ironwood network upgrade for Zcash may not arrive on schedule. Shielded Labs warned that exchanges, mining pools and wallets may not have sufficient time to prepare their systems before the activation planned for late July.
Jason McGee, executive director of Shielded Labs, posted on the Zcash community forum that two large-scale processes are advancing simultaneously: the activation of Ironwood and the migration of the zcashd node software and wallets to the so-called Z3 stack.
Update on Ironwood, from @aquietinvestor: https://t.co/KxHnXMr1SH pic.twitter.com/XYCyRndzkh
— zooko🛡🦓🦓🦓 â“© (@zooko) July 2, 2026
The “Infinity” Bug
The urgency surrounding Ironwood stems from researchers discovering a bug known as “infinity” in Orchard, Zcash’s primary private transaction pool. The flaw would have theoretically allowed an attacker to create unlimited amounts of fake ZEC tokens within the pool without leaving a trace. Developers indicated there is no evidence it was ever exploited, but Orchard’s privacy features make it impossible to prove with certainty that no counterfeit coins were generated. The price of ZEC dropped 40% after the incident was disclosed, even after the team announced a patch.
Ironwood Racing Against the Clock
Ironwood would open a replacement private pool and prevent new activity within the existing Orchard. Funds leaving Orchard will have to pass through an accounting checkpoint that prevents more ZEC from exiting than originally entered, allowing verification that the circulating supply remains within the limits defined by the protocol.
The migration from zcashd further complicates the picture. Its replacement is structured around three tools: Zebra to operate the network node, Zaino to supply blockchain data to applications and Zallet for wallet functions. The official documentation warns that some exchanges will need to modify their systems because certain zcashd functions will have no direct replacements. McGee noted that Zallet and Zaino are still under development and are not ready for production use. Surveys among infrastructure providers reveal that some expect to be ready by late July, while others require more time.
McGee clarified that no delay has been officially announced. Zooko Wilcox, founder of Zcash, confirmed that security reviews found no additional critical bugs and that developers are working to validate the new system before Ironwood takes effect.
