Glossary
Euler Hack (2023)
The March 2023 flash-loan donation attack that drained ~$197M from Euler Finance — fully returned by the attacker three weeks later after public negotiation.
On March 13, 2023, an attacker exploited a missing health-check
in Euler's donateToReserves function. By flash-loaning,
self-borrowing, and donating part of their position to reserves,
they pushed their own account into liquidatable territory and
then self-liquidated — capturing the soft-liquidation bonus
roughly 200 times in one transaction.
Total drained: ~$197 million across DAI, USDC, stETH, and WBTC. Euler then negotiated publicly with the attacker, who returned the entire amount over the following three weeks. The case is the most successful negotiated-return in crypto history.