Cysic suspended its cross-chain bridge after an attacker gained unauthorized access to a database supporting bridge operations and exploited message-processing logic to mint 10 million CYS tokens on BNB Smart Chain on Oct. 17, 2026. The attacker sold 7.2 million tokens, converting 5.65 million into about 588,315 USDT and 1.55 million into about 220 BNB, then used SWFT, Mayan and deBridge to move about 306.6 ETH worth roughly $727,000 to Ethereum. Cysic blacklisted the attacker's address about 76 minutes after the breach, blocking transfers of the remaining 2.8 million CYS on BNB Chain. The foundation said existing user assets and the Cysic mainnet were unaffected, while the final dollar loss remains under review. The bridge will stay offline as an outside security firm investigates the breach and traces the funds. Cysic is developing hardware for zero-knowledge-proof generation and a Layer 1 blockchain, and raised $6 million in a 2023 seed round led by Polychain Capital.