Cysic suspends its cross-chain bridge after an unauthorized mint of 10 million CYS on BNB Smart Chain

Summary

Cysic said in an Oct. 18 X post that on Oct. 17 an unauthorized mint of 10 million CYS occurred through its cross-chain bridge, that user wallets and mainnet operations remain unaffected, and that the bridge stays suspended pending a security review.

Cointelegraph, citing Cysic’s Sunday X incident report, said preliminary findings point to unauthorized access to a database supporting the bridge and a processing flaw that let an attacker mint 10 million CYS on BNB Smart Chain.

According to Cointelegraph, the mint occurred at 12:31:38 UTC and Cysic blacklisted the recipient address on the token contract at 13:47:52 UTC, leaving about 2.8 million CYS at that address with transfers restricted.

Cysic said via Cointelegraph that the incident was limited to bridge message processing and minting, did not involve theft of existing CYS or other assets from user wallets, and that the mint size alone does not establish the final dollar loss; the company said it has hired a security firm and plans a follow-up report.

Key facts

• Cysic said on X: “On Oct 17, a security incident involving the unauthorized minting of 10M CYS occurred through the Cysic bridge. Our team responded swiftly. User wallets and mainnet operations remain unaffected. The bridge remains suspended pending security review.” (Cysic (official X))
• The Cysic Foundation published an X Article titled “Cysic Incident Report” linked from its Oct. 18 post, which Cysic quoted in its update. (Cysic Foundation (X incident report))
• Cointelegraph reported that preliminary findings point to unauthorized access to a database supporting the bridge, and that the incident was limited to bridge message processing and minting and did not affect the mainnet or other operational systems. (Cointelegraph)
• Cointelegraph said the mint occurred at 12:31:38 UTC and Cysic added the recipient address to the token contract’s blacklist at 13:47:52 UTC, with about 2.8 million CYS remaining at that address under transfer restrictions. (Cointelegraph)
• Cointelegraph quoted Cysic as saying the incident “did not result in the theft or unauthorized transfer of existing CYS or other assets held in user wallets,” and that token transfers, swaps and actual losses remain under review. (Cointelegraph)
• Cointelegraph said Cysic has hired a security firm and plans to publish a follow-up report after the current investigation phase. (Cointelegraph)
• Cointelegraph noted that CYS coordinates incentives for users, compute providers, governance participants and contributors in Cysic’s network, according to the project’s tokenomics documentation. (Cointelegraph)