The Bitget hack resulted in approximately $387.5 million in stolen assets after attackers exploited a zero-day in a third-party security product and compromised Bitget’s wallet infrastructure. Rather than stealing private keys, the attackers forged withdrawal requests that Bitget’s own signing system accepted as legitimate, allowing valid signatures over unauthorized transfers.

On September 24, 2026, Payy lost $1.92 million in USDC after forged zero-knowledge proofs passed its verifier. This analysis reconstructs the Barretenberg soundness bug, the fix released 73 days before the exploit, and a Lean model demonstrating the missing constraint.