
Syscoin's bridge was exploited due to a transaction-proof validation flaw that allowed manipulated data to bypass verification, resulting in about 5 billion unauthorized SYS tokens being created. This flaw did not involve private key theft but a logic failure in the bridge's proof-verification process. The incident caused SYS's price to drop over 40%, highlighting the risks in cross-chain systems where validation errors can severely impact supply integrity and market confidence. The bridge is currently paused as the team works on remediation and tracing the affected funds.