TL;DR:
- Zcash set July 28 for the Ironwood upgrade to retire the compromised Orchard pool after an “infinity” bug disclosed in May.
- Ironwood closes Orchard, blocks new activity, creates a fresh private pool and requires funds leaving Orchard to pass an accounting checkpoint before entering Ironwood.
- ZEC fell 50% after the June 3 disclosure, later partially recovered, while more than 80% of the maximum 21 million ZEC supply is now issued.
Zcash has set July 28 for the activation of Ironwood, a network upgrade designed to retire Orchard, the privacy pool compromised by an “infinity” bug disclosed in May. The fix is more than routine maintenance for a chain whose value proposition depends on confidential transfers and monetary certainty. Ironwood will close the existing Orchard pool, block new activity there and create a fresh private pool. Funds leaving Orchard must pass through an accounting checkpoint before entering Ironwood, meaning the upgrade turns migration into a forensic test for whether counterfeit ZEC was ever created.
Zcash's Ironwood mainnet activation height has been set and tagged! All of the major organizations are committed to activation of NU6.3 at height 3428143, which is approximately July 28th at 8AM EST.
— Sean Bowe (@ebfull) July 9, 2026
Sean Bowe, a Zcash core developer, said the mainnet activation height has been set at 3,428,143, approximately July 28 at 8AM EST, with major organizations committed to activating NU6.3. The timing follows concern from Shielded Labs that exchanges, mining pools, wallets and other ecosystem participants might not have enough preparation time for a late-July upgrade. The schedule is also one week later than an earlier July 21 target. The extra week still leaves little margin, but it signals coordination around fixing a vulnerability that threatened confidence across the network’s core economic assumptions.
Ironwood turns a privacy fix into a supply audit
The most consequential feature is how Ironwood handles movement out of Orchard. Shielded Labs said in June that the upgrade may provide evidence about whether the vulnerability was exploited. As users migrate funds, any hypothetical counterfeiter faces an awkward choice: try to move counterfeit funds and risk revealing their existence, or leave them behind and risk losing the ability to move them later. That makes the pool transition unusually revealing, even for a privacy-focused network built to minimize public visibility.
The market has already priced some damage. ZEC dropped 50% after the June 3 Orchard bug disclosure, falling from $602.68 to $299.25, before partially recovering to $492.61 at the time of the report. Zcash also crossed a monetary milestone this week, with more than 80% of its maximum 21 million ZEC supply now issued and 16,806,723 ZEC in circulation. Ironwood therefore arrives at a delicate moment, where technical repair, supply confidence and market psychology meet. If activation succeeds cleanly, Zcash may regain some credibility. If migration exposes problems, the upgrade could become the beginning of a much harder accounting and trust crisis. Users will watch the monetary ledger very carefully throughout the migration process ahead.
