Cross-chain liquidity protocol Symbiosis says it recovered roughly 15 BTC and offered the attacker a 20% white-hat bounty after a vulnerability in its native Bitcoin Bridge was exploited on September 11. The team disclosed the incident on its official X account , stating that only the Bitcoin Bridge was affected and that its other routes remain operational and safe. The disclosure adds to a string of bridge security incidents that have rattled the sector in recent weeks.
What Happened to the Bitcoin Bridge
According to Symbiosis, an attacker exploited a vulnerability in the Bitcoin Bridge at approximately 04:28 UTC on September 11, 2026. The breach enabled the minting of a synthetic bitcoin representation, syBTC, on BNB Chain, echoing the Polkadot bridge exploit in which an attacker minted one billion DOT on Ethereum. Symbiosis immediately halted BTC routes and isolated the affected bridge from its other components, which include routes spanning EVM chains, TRON, and TON. The protocol stressed that those unaffected routes continue to operate normally and that its relayer group remains active to secure the network.
Recovery and the 20% Bounty
The protocol said it recovered approximately 15 BTC, now secured in a team-controlled multisig, and that it has contacted the attacker with a white-hat bounty offer equal to 20% of the funds. That window is open until September 13, 2026, after which the same 20% will be offered to anyone providing information that leads to recovery. Symbiosis cautioned that final accounting remains in progress and said it will publish confirmed figures in a further update, leaving the exact total exposure of the bridge’s liquidity providers unresolved for now.
Bitcoin Bridge Remains Paused
While the native Bitcoin Bridge stays paused, Symbiosis said in a follow-up update that Bitcoin swaps are back online through its partners Chainflip and THORChain. The detour arrives as the bridge sector faces renewed pressure: Chainflip paused its own Tron integration after a $736,000 USDT exploit earlier this week. Symbiosis has not said when the Bitcoin Bridge will reopen, and affected liquidity providers are still awaiting clarity on compensation terms. The protocol said it will share a separate update once the native bridge is restored.
