Cysic Bridge Unbacked CYS Mint
An attacker abused Cysic's bridge to mint 10 million unbacked CYS on BNB Chain, dumping most of it for about $727,000 in ETH before the token could be blacklisted.
Vuln-watch · relayed from a public source; see Source & attribution below
Summary
An attacker abused Cysic's bridge to mint 10 million unbacked CYS on BNB Chain, dumping most of it for about $727,000 in ETH before the token could be blacklisted.
Incident
- Victim: Cysic
- Date (UTC): 2026-10-17
- Estimated loss: $727k
- Chain(s): BNB Chain, Ethereum
- Attack type: bridge exploit
- Funds status: stolen
- Attacker:
0xA4e1827Fe2664fD0797a55e442b2e2639449C255
Recommended actions
- Revoke token approvals granted to Cysic contracts until the project confirms they are safe
- Integrators: pause or delist affected assets and monitor for attacker fund movements
- Beware of follow-on phishing: ignore unofficial "refund", "recovery", or "claim" links and DMs; use the project's verified channels only
Source & attribution
Full analysis on Blockchain Breaches, 0xCERT's incident archive: https://www.blockchainbreaches.com/en/breaches/cysic-2026. Primary sources: https://www.cryptotimes.io/2026/10/19/cysic-bridge-hack-attacker-mints-10m-cys-moves-727k-to-ethereum/ ; https://cryptoadventure.com/cysic-halts-bridge-after-10-million-cys-exploit-sends-727k-to-ethereum/.
References
Indicators of compromise
All IOC feeds →- address0x1106de394da07e90b02161465ea0421b74db4691Second wallet that received ~306.52 ETH of Cysic exploit proceeds from the attacker (The Block) · Ethereum
- address0xa4e1827fe2664fd0797a55e442b2e2639449c255Cysic bridge exploit attacker: received 10M unbacked CYS mint (Cysic Foundation incident report; The Block) · BNB Chain
- address0xa4e1827fe2664fd0797a55e442b2e2639449c255Cysic bridge exploit attacker address on Ethereum, received bridged proceeds (The Block) · Ethereum
- tx0x8de43ba77f9a14ecff1268acb9d7c9bf3afe1f2a45bd8d8681d824a2460000f6Unauthorized 10M CYS mint via Cysic bridge (The Block) · BNB Chain
OpenPGP-signed. The signed text of this advisory verifies against the 0xCERT key CCC7 D9EC 9415 723D.
Published 2026-10-17 · last updated 2026-10-19
curl -s https://www.0xcert.com/pgp.asc | gpg --import && curl -s https://www.0xcert.com/advisory/0xCERT-2026-0255/signed.txt | gpg --verify