A hacker turned 25 cents of bitcoin into 46 billion fake BTC tokens on a DeFi bridge

MonitoringCryptoSecurity incidentFirst tracked 2026-09-15Last changed 2026-09-15

Current outcome

Two software flaws in Symbiosis' Bitcoin Bridge let an attacker mint roughly 46.1 billion unbacked syBTC from a 330-satoshi deposit, with the protocol estimating real losses at 9.97 BTC and taking the bridge offline for a rewrite and audit.

Progress timeline

1 material updates

#0109.15
Initial2026-09-15 13:43 · publication time
A hacker turned 25 cents of bitcoin into 46 billion fake BTC tokens on a DeFi bridge
Two software flaws in Symbiosis' Bitcoin Bridge let an attacker mint roughly 46.1 billion unbacked syBTC from a 330-satoshi deposit, with the protocol estimating real losses at 9.97 BTC and taking the bridge offline for a rewrite and audit.
Source evidence: CoinDesk

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