ZEC rebounds 42% as ZODL founder details two-step emergency upgrade

Josh Swihart, founder of Zcash Open Development Lab (ZODL), has provided further details on how the Zcash team resolved a critical vulnerability in the Orchard shielded pool. In a Sunday post on X, Swihart wrote that the ZODL team has dispatched a two-step emergency upgrade for the privacy-focused blockchain network Zcash.

The first step was a soft fork designed to disable Orchard transactions and mitigate the "risk of an exploit without revealing the full scope of the issue before responsible disclosure," Swihart said. A follow-up hard fork, dubbed NU6.2, was activated on June 3 to address the underlying issue and re-enable Orchard transactions, per the post.

The move comes after independent support group Shielded Labs disclosed a severe vulnerability in Zcash's Orchard pool that, in theory, exposed the network to unlimited minting of counterfeit ZEC. The group said the bug had been fixed and that it was unlikely an actual exploit ever took place — small comfort for anyone watching the chart.

Orchard is Zcash's main shielded transaction pool, letting users send and receive ZEC with full zero-knowledge privacy. The Orchard circuit is the zero-knowledge proof system that verifies only valid transactions make it through.

Swihart also noted that ZODL fielded requests from mining pools and exchanges for code reviews to verify the team's work, adding that ViaBTC and Foundry played a key role in coordinating the response. Nothing says "trust us" quite like a last-minute audit under pressure.

Shielded Labs' disclosure last Thursday rattled market confidence, sending ZEC down more than 50% from around $630 to a low of roughly $303. Many traders, drawn in by Zcash's zero-knowledge pitch, suddenly found themselves questioning the protocol's long-term security and reliability — a reasonable reaction to a bug that, on paper, could have printed money out of thin air.

Among them was BitMEX co-founder Arthur Hayes, who announced he had liquidated his entire ZEC position following the vulnerability disclosure. Timing, as they say, is everything.

ZEC has since recovered partially, rising 13.5% over the past 24 hours to trade at $428.67, according to The Block's price page. That marks a 41.5% bounce from the June 5 low of $303.

"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," Swihart wrote.

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