Zcash plummets 30% as Shielded Labs reveals a major bug that went undetected for four years
Zcash (ZEC) fell about 30% to around $400 amid broader market weakness after Shielded Labs disclosed a critical vulnerability in Zcash’s Orchard privacy pool. The bug could have let an attacker create unlimited counterfeit ZEC without detection, threatening confidence in the token’s supply. A security engineer, Taylor Hornby, found the flaw on May 29 while reviewing the Orchard circuit with help from Anthropic’s Opus 4.8 model, built a working exploit in a local test environment, and reported it immediately. Zcash Open Development Lab coordinated an emergency fix on June 1. Markets reacted negatively because the bug had existed since Orchard launched in May 2022, and it is impossible to prove from cryptography alone whether it was ever exploited. Shielded Labs said exploitation likely did not occur, but uncertainty remains. It is proposing a network upgrade to improve supply verification and is accelerating further security work, including formal verification and new security hires.
