What happened
On August 10, 2025, an attacker manipulated collateral valuation in Numa's Sonic lending system and liquidated other users' positions. Flash-loaned assets were used to mint nuBTC, increasing the protocol's synthetic liabilities and sharply lowering the computed value of cNuma collateral without a corresponding loss of vault assets. Incident analyses estimate about $313,000 in proceeds; the catalog lists approximately $320,000.
How it happened
- The attacker flash-borrowed stS and acquired NUMA, then opened a cNuma-backed borrowing position.
- They minted about 3.08 nuBTC. Because the cNuma valuation formula subtracts synthetic liabilities from vault assets, this caused the computed collateral price to fall sharply.
- Accounts that had been sufficiently collateralized became liquidatable at the manipulated price. The attacker liquidated them, seized assets, unwound the synthetic position and repaid the flash loan.
Protocol details
Classification
Protocol Logic / Token & Share Accounting
Protocol Type
DeFi Protocol
Implementation language
Solidity
Evidence
- report @CertiKAlert incident report x.com
- analysis DeFiLlama defillama.com
- analysis Numa Incident Analysis www-cn.certik.com
- analysis Numa Incident Analysis blog.verichains.io
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