Symbiosis BridgeV2 Exploited for 46 Billion Fake Tokens

Symbiosis, a cross-chain protocol, was hit by an attacker who exploited its BridgeV2 contract on BNB Chain, minting approximately 46.1 billion fake syBTC tokens.

The attack triggered a signed 'receive' function, allowing the attacker to bypass security measures and create unbacked tokens.

Despite the massive scale of the exploit, the attacker's realized cash-out was relatively small, with Blockaid estimating about 4.39 wrapped bitcoin sold through Uniswap, netting roughly $336,000.

Symbiosis moved quickly to contain the fallout by isolating the compromised system and suspending native Bitcoin routing while keeping other cross-chain rails running.

The protocol recovered around 15 BTC into a team-controlled multisignature wallet and clarified that all routes remain operational, with the exception of its native Bitcoin bridge, which remains paused.