Hedera-based lending protocol Bonzo Lend lost about $9.05 million after an attacker manipulated the price of SAUCE used as collateral. Bonzo Finance Labs said the incident began on July 11, 2026, when a wallet submitted a false SAUCE price to a third-party Supra oracle contract. The attacker deposited 250 SAUCE, worth only a few dollars, before the feed treated the tokens as highly valuable.
Summary
- An attacker inflated SAUCE’s oracle price and borrowed assets worth about $9.05 million from Bonzo.
- Supra’s verifier accepted a zeroed signature, allowing the false price update to reach Hedera mainnet.
- Bonzo paused lending while teams pursue recovery, fixes, and the promised return of white-hat funds.
Eight seconds after the false price reached the network, the wallet borrowed 6.63 million USDC and more than 34.5 million wrapped HBAR. Bonzo described the headline loss as “approximately $9.05 million.” The protocol paused Bonzo Lend at 01:41 UTC and stopped Bonzo Points later that morning. Bonzo Vaults, Bonzo Bridge, and single-sided BONZO staking continued operating.
Zeroed signature passed Supra’s verifier
Bonzo’s incident report traced the event to Supra’s signature verification process. The update carried a zeroed signature instead of a valid signature from Supra’s oracle committee. Bonzo said the verifier failed to reject zero-value inputs before sending them to Hedera’s pairing system contract.
The pairing check returned true because both values represented the mathematical identity point. Supra’s contract then treated that result as proof of a valid committee signature. Bonzo said “no valid oracle signature was forged” and SAUCE’s real market price did not rise. Supra has since deployed a fix to the affected verifier contract on Hedera mainnet, according to the report.
Bonzo says its lending contracts followed their code
Bonzo said its lending contracts read the manipulated value from the approved oracle feed and calculated borrowing power from that data. The team stated that the lending pool acted as designed after receiving the false input. Its report ruled out a Bonzo contract bug, a flash-loan attack, and normal market manipulation.
A second account borrowed about $1 million while the abnormal price remained active. That wallet later contacted the team and described itself as a white-hat responder. It said it planned to return the assets. Bonzo excluded that amount from its $9.05 million loss figure because recovery talks remain active. The published report had not confirmed the return.
Crypto.news tracked transfers before Bonzo confirmed the loss
Before Bonzo released its findings,crypto.news reported that security researchers had tracked more than $5.8 million moving from Hedera to Ethereum. Researchers said the wallet bridged assets through LayerZero and converted part of the holdings from wrapped Bitcoin into Ether. HBAR fell more than 2% as the transfers continued.
Bonzo’s oracle documentation lists Supra feeds for SAUCE, HBARX, XSAUCE, DOVU, PACK, KARATE, STEAM, and HST against wrapped HBAR. The incident affected the SAUCE pair. Bonzo said legitimate publishing restored that price to about 0.1964 HBAR at 01:36 UTC, five minutes before the lending pool pause.
The later Bonzo report raised the confirmed principal taken by the main attacker to about $9.05 million. A Wu Blockchain post also shared the protocol’s findings. Bonzo Lend remains paused while Bonzo Finance Labs and the Bonzo Finance Foundation work with partners on asset recovery, repairs, and withdrawal plans for liquidity providers. The team has not set a date for reopening the lending pool.
