How Summer.fi's $6M Exploit Was Months in the Making

The Real Attack Vector

The report challenges the early narrative that this was a simple flash loan attack. Blockchain evidence shows the attacker funded multiple wallets roughly three months before the incident and gradually accumulated stale-valued Silo vault tokens. Those tokens were later used to inflate the NAV. The flash loans provided temporary liquidity for the final transaction – they did not create the vulnerability itself.

Summer.fi also addressed a widely shared screenshot showing an annual percentage yield of roughly 2.08 million%. The figure came from a one-block spike in the vault's reported NAV and did not represent actual returns.

What Happens Next

All Lazy Summer Protocol vaults were paused after the exploit, and deposit caps were reduced to zero while the incident was investigated. The report says governance must now decide how to handle the affected vaults, whether to compensate users, and when unaffected vaults can safely resume operations.

The attacker's three-month preparation is the detail that should give pause. Opportunistic flash loan attacks get patched quickly. A patient operator who identified an accounting gap in an offboarding process – and waited months to strike – suggests a different class of risk. The protocol's next steps on compensation and re-opening will test how well DeFi governance handles operational failures that are not code bugs.