Ostium Drains $18 Million After Attacker Submits Future-Dated Oracle Data via Privileged Keeper Role

A hacker drained $18 million in USDC from Ostium's liquidity vault on Arbitrum on July 15, 2026, by submitting falsified future-dated oracle data through the protocol's automated price-reporting system. CoinDesk reported that the attacker used a registered PriceUpKeep forwarder component to deliver manipulated oracle reports with future timestamps.

The altered data made losing trades appear profitable and triggered the payout.

Blockchain security firm Blockaid detected the exploit through onchain monitoring. Ostium operates as a decentralized perpetuals exchange on Arbitrum that supports trading in gold, forex and equity indices with leverage up to 200x and settlement in USDC. The platform relies on a custom price-feed system in which Gelato pushes prices onchain.

A $6 million exploit at Summer.fi the prior week followed a similar pattern of keeper and oracle manipulation. Ostium had raised $27.8 million in total funding, including a $24 million Series A round co-led by General Catalyst and Jump Crypto in late 2025, and had processed more than $50 billion in cumulative trading volume before the incident.