Symbiosis Recovers 15 BTC After Bridge Exploit, Offers 20% Bounty

Cross-chain bridges lock assets on one blockchain and issue claims on another, allowing capital to move between otherwise incompatible networks such as Bitcoin and Ethereum. Their security depends not only on smart-contract code but also on validation logic, private keys and administrative upgrade controls. The cluster of breaches matters because none required attackers to break underlying cryptography; instead, recurring governance and permission failures allowed trusted components to release or redirect funds.

During a six-hour span ending July 23, 2026, at least three systems lost more than $35 million. AFX Trade’s Arbitrum bridge was drained of about $24.15 million, the Verus-Ethereum Bridge lost $7.54 million, and B² Network lost $3.86 million after an attacker seized the upgrade authority for its staking contract. Blockaid said the Verus incident reused the contract path and vulnerability class exploited on May 18; Verus had redeposited recovered funds into the bridge on July 8. B² suspended staking and said affected users would be fully compensated.