Wanchain Offers Cardano Bridge Hacker 10% Bounty, Sets August 6 Deadline for Return of Stolen NIGHT Tokens

Wanchain is offering a 10% white-hat bounty to the hacker who exploited its Cardano bridge on July 20, 2026, stealing 515.2 million NIGHT tokens worth $10 million. The protocol set an August 6, 2026 deadline for the return of 90% of the funds in exchange for dropping civil claims. The exploit, caused by a signature reuse vulnerability, adds to over $1.1 billion in crypto losses during the first half of 2026.

Wanchain Cardano bridge exploit

• ▪The stolen 515.2 million NIGHT tokens from the Wanchain Cardano bridge exploit were valued at approximately $10 million
• ▪The Wanchain cross-chain bridge protocol on Cardano was exploited on July 20, 2026, resulting in the theft of approximately 515.2 million NIGHT tokens

White-hat bounty offer terms

• ▪Wanchain pledged not to pursue civil claims against the Cardano bridge hacker if the 90% return offer is accepted
• ▪Wanchain set a deadline of August 6, 2026, at 12:00 UTC for the Cardano bridge hacker to return the stolen NIGHT tokens
• ▪Wanchain offered the Cardano bridge hacker a 10% white-hat bounty to retain 10% of the stolen NIGHT tokens if they return the remaining 90%

Bridge vulnerability technical details

• ▪The Wanchain Cardano bridge exploit was caused by a non-injective signed-message encoding flaw in the TreasuryCheck validator
• ▪Security firm BlockSec's Phalcon monitoring system first flagged the Wanchain Cardano bridge exploit on July 21, 2026
• ▪The Wanchain Cardano bridge vulnerability stemmed from raw concatenation of variable-length fields without proper delimiters, allowing signature reuse

Blockchain monitoring recovery efforts

• ▪Wanchain engaged blockchain analytics firms and flagged the relevant hacker addresses with cryptocurrency exchanges for monitoring
• ▪Wanchain temporarily disabled the Cardano-BNB Chain bridge following the July 20, 2026 exploit

2026 crypto hack statistics

• ▪Total losses from cryptocurrency security incidents surpassed $1.1 billion across 212 verified attacks in the first half of 2026
• ▪North Korean hacking groups, specifically the TraderTraitor subgroup of the Lazarus Group, were linked to the KelpDAO, Drift Protocol, and Humanity Protocol exploits
• ▪Four major attacks on KelpDAO, Drift Protocol, Resolv, and CowSwap accounted for approximately $707 million, or 64% of all crypto losses in the first half of 2026

White-hat negotiation controversy

• ▪Bridge vulnerabilities remain one of the largest sources of losses in the digital asset industry, exposing users and liquidity providers to significant risks
• ▪White-hat bounty agreements have sparked debate over whether such offers incentivize attackers to negotiate after executing an exploit