Blockaid found attackers exploited a vulnerability in Symbiosis's Bitcoin bridge, minting roughly 2^62 syBTC and converting a real ≈4.39 WBTC into about $336,000 via Uniswap V4. Symbiosis suspended BTC routing and recovered ≈15 BTC into a multisig.
• The protocol offered attackers a 20% whitehat bounty.
• The nominal ≈$46.1B syBTC figure was a display/overflow artifact.
Matters because: it is the third bridge-related mint exploit in recent weeks, reinforcing recurring supply-integrity failures in cross-chain bridges.