Zcash Surges 42% After ZODL Outlines Two-Step Orchard Fix

Zcash’s token ZEC jumped roughly 42% after Josh Swihart, founder of the Zcash Open Development Lab (ZODL), described a two-step emergency response to a flaw in the network’s Orchard shielded pool.

ZODL deployed a soft fork first to disable Orchard transactions and limit the risk of exploitation while details were handled through responsible disclosure. A hard fork, NU6.2, was activated on June 3 to repair the underlying circuit error and re-enable shielded activity.

Independent security group Shielded Labs disclosed the vulnerability in the Orchard circuit, saying the flaw could have allowed unlimited creation of counterfeit ZEC. Shielded Labs reported the bug had been corrected and assessed it unlikely that the vulnerability was exploited in practice. Orchard is Zcash’s most recent shielded pool; it uses zero-knowledge proofs to confirm transactions are valid without revealing sender, receiver or amounts.

ZODL coordinated the emergency response with mining pools and exchanges and provided code reviews to operators seeking verification. Swihart highlighted cooperation with mining pools ViaBTC and Foundry as part of the coordination and review effort.

Markets reacted sharply after the initial disclosure. ZEC fell more than 50% from about $630 to a low near $303 following the report of the vulnerability. One notable investor, Arthur Hayes, announced he had liquidated his ZEC holdings after the disclosure. After the hard fork and public updates from ZODL, ZEC traded around $428.67, a roughly 13.5% increase over 24 hours and about a 41.5% recovery from the June 5 low.

Swihart wrote that the incident tested the team’s incident-response procedures and strengthened relationships with other network participants. “We resolved the issue, battle-tested our incident support processes, built stronger relationships with others who support the network, tested our own resilience, and unified as a community of builders to agree on a path forward,” he wrote.

Developers and network operators have continued code reviews and monitoring since the hard fork to confirm the fix and rebuild confidence among users and service providers. ZODL indicated it will keep working with pools and exchanges to review future changes and respond to any new concerns.