Zcash Orchard flaw prompts emergency fix and Ironwood supply-verification proposal

After an emergency soft fork and the NU6.2 hard fork on June 3 fixed a severe vulnerability in Zcash’s Orchard shielded pool, developers proposed and then completed the consensus changes for the Ironwood upgrade, which is targeted for activation in July. The flaw, disclosed by Shielded Labs, could theoretically have allowed unlimited counterfeit ZEC inside private Orchard transactions, though the group said exploitation was unlikely and there is still no proof whether fake ZEC was ever created or withdrawn into wider circulation. Ironwood is designed to let node operators verify supply against Zcash’s expected mining schedule while replacing the old Orchard pool with a new privacy pool that uses turnstile accounting and a flag mechanism to restrict deposits into the old pool. ZEC partially rebounded after an initial plunge of more than 50% but remained down about 21% to 22% for the week, while ThorChain delayed its planned ZEC integration and Arthur Hayes said he sold his entire position.