Researcher Who Found Zcash Bug Adds Monero to Audit Queue, XMR Price Falls 10%

Security researcher Taylor Hornby plans to add Monero (XMR) to his audit queue after using Anthropic’s Claude Opus 4.8 to expose a critical counterfeiting flaw in Zcash (ZEC).

Hornby confirmed the move when asked whether he could probe other privacy coins. His Zcash discovery erased roughly 30% from ZEC before developers shipped an emergency patch.

$XMR holders should pay attention🚨The researcher who discovered the bug that wiped 50% off $ZEC is now adding Monero to his audit queue.Does that mean Monero has a bug?NoBut after what happened to Zcash, the market might not wait around to find out. https://t.co/NrHoy8NhIJ pic.twitter.com/5l0QG1C8kp

— Kapoor Kshitiz (@kshitizkapoor_) June 6, 2026

How an AI Audit Found the Zcash Bug

Hornby, commissioned by nonprofit developer Shielded Labs in April, ran a custom auditing agent paired with Opus 4.8 on May 29.

Within a day, he flagged a soundness flaw in the Orchard shielded pool. Anthropic had released the model only a day earlier, making the find one of its first high-profile security catches.

The bug, an under-constrained elliptic curve check, had survived since Orchard launched in May 2022. It could have minted unlimited, undetectable ZEC counterfeits within the pool.

Engineers closed the hole on June 2. Shielded Labs said prior exploitation looks unlikely but cannot be ruled out cryptographically, a tension central to the AI-assisted Zcash bug disclosure.

Why Monero Is Next

Monero is the largest default-privacy cryptocurrency. It hides every transaction by design rather than offering Zcash’s optional shielding.

A recent Monero network upgrade added further privacy features, widening the surface Hornby could examine in the ongoing privacy coin race.

Absolutely! I'll add Monero to my queue of things to audit

— Taylor Hornby 🛡❤️ (@DefuseSec) June 5, 2026

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He said other privacy-focused projects also sit on the list. He intends to apply for a Zcash coinholder grant to fund the work.

“To get ahead of scams, if you’re interested in donating to me for finding the Zcash bug, my addresses are in this post or in my replies below…donations are much appreciated but not necessary!” Taylor Hornby appealed.

ZEC has since steadied near $363, recovering by nearly 20% in the last 24 hours. As of this writing, the Zcash token was trading for $373.27.

In turn, Monero’s XMR token has fallen by nearly 10%, and was trading for $298.76 as of this writing.

Meanwhile, as institutions holding ZEC weigh the fallout, a formal verification push backed by the Winklevoss twins now aims to prevent similar flaws.

The episode shows AI tools surfacing bugs that human reviewers missed for years.