Lack of liquidity in the Uniswap V3 FLOAT/USDC oracle allowed an attacker to manipulate the prices within the pool, then deposit it at a much higher rate. The hacker pulled about 350 ETH (equivalent to $1.1 million) out of the pool, though according to PeckShield they later returned around $250,000 for some reason.

Total loss estimated at $850,000.