Zcash surged more than 80% from its Friday low after developers patched a critical vulnerability in its Orchard shielded pool and proposed a new network upgrade designed to restore confidence in the privacy coin's circulating supply.
ZEC jumped from about $250 on Friday to more than $450 by Monday morning, reversing part of a steep selloff triggered by the disclosure of a bug that could have allowed an attacker to create counterfeit ZEC inside Orchard.
The token was recently trading near $450, with a market capitalization of about $7.4 billion and more than $1 billion in 24 hour trading volume.
The rebound followed a coordinated emergency response by Zcash developers and ecosystem participants, who patched the issue through a network upgrade completed on June 2.
Shielded Labs said the vulnerability was unlikely to have been exploited, while ZODL said there was no evidence of impact to user funds, no evidence of any change to total ZEC supply, and no evidence that the flaw affected privacy.
Still, the incident created a confidence problem for Zcash. Orchard is a shielded pool, meaning transaction details are hidden by design. That privacy protects users, but it also means users cannot independently prove that no counterfeit ZEC was ever created inside the pool.
Developers are now trying to solve that problem with Ironwood, a proposed upgrade being developed by ZODL alongside Tachyon, Valar Group, the Zcash Foundation, and Shielded Labs.
The new shielded pool would use the existing Orchard protocol with the recent vulnerability fixed, while adding formal verification and independent audits intended to reduce the risk of future soundness bugs.
Ironwood would also close the current Orchard pool to new deposits and internal transactions. Funds would only be able to move out through a turnstile, Zcash's accounting mechanism for transfers between pools. Because the turnstile rejects any attempt to move out more ZEC than entered, users would be able to verify that no more than the correct amount of ZEC is circulating.
That design is meant to give Zcash users a trustless supply check without requiring them to wait for everyone to migrate from Orchard. Once Ironwood activates, users running a node would be able to verify the soundness of circulating supply by checking the balances of active pools.
ZODL said it is targeting activation for late July 2026, after zcashd reaches end of support at block height 3,417,100. The timing remains subject to testing, review, and coordination across wallets, node operators, exchanges, mining pools, and infrastructure providers.