Zcash Jumps as Orchard vulnerability patch disables counterfeit mint risk, Grayscale weighs exploit odds

Zcash (ZEC) rebounded sharply in early trading after a security incident earlier in the week prompted heavy selling. Multiple reports said ZEC surged roughly 16% on the day and, in one case, about 45% from the prior week’s low, following steps to address the reported problem affecting its privacy infrastructure ^{[1] [2]}.

The selloff was linked to a critical Orchard shielded-pool vulnerability, described as having been present since May 2022 and tied to the risk of counterfeit ZEC through unauthorized minting. An emergency soft fork on June 2 disabled the vulnerable feature, with a follow-up hard fork (NU6.2) deploying the permanent fix the next day, according to one account; another report said developers proposed an “Ironwood” upgrade intended to let anyone confirm no counterfeit ZEC is circulating ^{[2] [3]}.

Market and risk assessments also circulated alongside the technical updates. Grayscale’s chief legal officer, Craig Salm, argued that signals from Zcash’s own shielded user base may provide more informative insight into exploit risk than external prediction markets, after Polymarket opened a contract related to whether the Orchard pool vulnerability was exploited on mainnet ^[4].

ZEC’s bounce follows protocol changes aimed at neutralizing the Orchard vulnerability and accompanying plans to reduce counterfeit risk, while observers continue to track whether the incident was actually exploited and how markets price the remaining uncertainty ^{[1] [4] [2] [3]}.