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Josh Swihart, founder of Zcash Open Development Lab, said the team moved fast after a critical flaw surfaced in Zcash’s Orchard shielded pool. The team first used a soft fork to disable Orchard transactions and limit exploit risk.
It then activated hard fork NU6.2 on June 3 to restore the feature after fixing the issue. The disclosure shook confidence, pushed ZEC lower, and sparked fresh debate over privacy coin security.
Swihart said the first step aimed to reduce risk without exposing the full problem before responsible disclosure. The soft fork paused Orchard transactions while the team worked on the deeper fix. That move gave the network time to respond before any confirmed exploit could spread.
A follow-up hard fork, NU6.2, went live on June 3. The upgrade addressed the root issue and brought Orchard transactions back online. Swihart said the team used the incident to test its response process and strengthen coordination across the network.
He also said ZODL responded to code review requests from mining pools and exchanges. According to Swihart, ViaBTC and Foundry helped coordinate the response. Shielded Labs had earlier disclosed the vulnerability and said the bug had been fixed.
Shielded Labs said the flaw could have allowed unlimited minting of counterfeit ZEC. It added that an actual exploit appeared unlikely. Even so, the disclosure rattled market confidence and sent ZEC sharply lower.
The price fell more than 50%, from about $630 to roughly $303. The token later recovered part of those losses. It rose 13.5% over the next 24 hours to trade at $428.67, according to The Block’s price page.
Swihart said the incident pushed builders to unify around a path forward. He said the response tested the network’s resilience and support systems. At the same time, the episode raised wider questions about the long-term security of privacy-focused blockchain networks.
Read More: Zcash Crashes as Orchard Vulnerability Sparks Supply Integrity Fears
ZODL later said it wants to introduce a new upgrade and shielded pool called Ironwood. The proposal includes Tachyon, Valar Group, the Zcash Foundation, and Shielded Labs. The team said Ironwood would build on Orchard with formal verification, and he will review Monero. ion and extra independent audits.
The group described Ironwood as the next step in hardening the Zcash protocol. It plans to strengthen the system while keeping the privacy model at the center of the network. The proposal follows the emergency response and the restoration of Orchard transactions.
Security engineer Taylor Hornby, who found the Zcash flaw using Anthropic’s Opus 4.8 AI model, also said he plans to review Monero. He found the Zcash issue on May 29. The vulnerability could have let hackers drain funds from the privacy pool for years, and Zcash fell 38% within 24 hours after the news broke.
Zcash contained a critical Orchard shielded pool vulnerability through a two-step emergency upgrade that included a soft fork and the NU6.2 hard fork. While the disclosure triggered a sharp ZEC price decline, the network restored operations and proposed the Ironwood upgrade as security reviews continue across privacy-focused cryptocurrencies.
