Critical Vulnerability Discovered in Zcash Orchard Pool Allows Unlimited Counterfeit Minting

• •A critical vulnerability in Zcash's Orchard pool allows unlimited counterfeit ZEC minting.
• •The flaw existed undetected since May 2022 and was discovered using AI-assisted methods.
• •Zcash developers patched the vulnerability quickly, but market concerns led to a 30% drop in ZEC price.

On May 29, 2026, security researcher Taylor Hornby uncovered a critical vulnerability in Zcash's Orchard shielded pool, enabling the potential minting of unlimited counterfeit ZEC tokens. The flaw, which had existed since the pool's launch in May 2022, was discovered using Anthropic's Opus 4.8 AI model. Following the disclosure, Zcash developers swiftly patched the vulnerability on June 1, 2026. However, the nature of the vulnerability makes it impossible to cryptographically verify if any counterfeit ZEC was created before the patch. The price of ZEC plummeted by over 30% following the announcement, reflecting market concerns about the integrity of the token supply. Zcash founder Zooko Wilcox emphasized that the vulnerability had evaded scrutiny from top cryptographers for years, suggesting a low likelihood of prior exploitation. Shielded Labs is proposing a network upgrade to enhance supply verification and prevent future issues. The incident highlights the challenges of maintaining privacy while ensuring security in cryptocurrency systems.