NCCapital

Privacy-focused cryptocurrency Zcash dropped sharply after Shielded Labs disclosed a serious vulnerability in its Orchard shielded pool that could have allowed unlimited, undetectable counterfeit token creation.

The critical bug had been present since the Orchard upgrade launched in May 2022. It was discovered on May 29, 2026, by security engineer Taylor Hornby, who used Anthropic’s newly released Opus 4.8 AI model to identify the flaw. An emergency patch was deployed by June 1.

Shielded Labs stated there is no cryptographic way to determine whether the vulnerability was exploited before the fix. In response, the team is proposing a network upgrade that includes new accounting measures and expanded security efforts to help restore confidence in ZEC’s token supply integrity.