# Oracle Key Compromise and an Account-Delegation Bug Lead the Week's Exploit Files

Ostium's post-mortem confirmed a $23.75 million vault loss from fake signed price reports, while new proof-of-concept code documents a token drained through Ethereum's account-delegation feature.

- Published: 2026-08-06T05:33:07.606Z
- Canonical: https://polylog.news/crypto/2026-08-06/oracle-key-compromise-and-an-account-delegation-bug-lead-the
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [Rekt News](https://www.rekt.news/), [DeFiHackLabs](https://github.com/SunWeb3Sec/DeFiHackLabs/commit/c25c91d221d2b5204f946e66e97601009a4f6bcb), [DeFiHackLabs](https://github.com/SunWeb3Sec/DeFiHackLabs/commit/d9bcd648ae761ffc3c7cbda129593c5e5269cf21)

The most expensive incident in this group did not involve a contract bug at all. Ostium, a perpetual futures venue on Arbitrum, lost 23,752,746 USD Coin from its liquidity vault after an attacker obtained the private key of an off-chain pri…

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