Cysic suspended its cross-chain bridge after an attacker exploited a processing flaw to mint 10 million CYS on BNB Smart Chain on Oct. Preliminary findings identified unauthorized access to a database supporting bridge services and a fraudulent mint message submitted through the bridge’s processing system.
The mint occurred at 12: 31: 38 UTC. About 2. 8 million CYS remained in the wallet and could no longer be transferred.
Cysic said the incident was confined to bridge message processing and token minting. Its mainnet, other operational systems and assets already held in user wallets were not affected, while the blacklist applied only to CYS on BNB Smart Chain and did not restrict the ether on Ethereum.
The foundation said the number of tokens minted does not by itself establish the final dollar loss. Transfers, swaps and verified losses remain under review, and the bridge will stay closed until a security review is complete. Cysic said it will publish a follow-up report on verified losses and efforts to trace the funds.