What happened
On July 30, 2026, Index Coop's ExchangeIssuance contract, associated with Set Protocol, lost approximately $9,600 in WETH and UNI. The incident did not involve compromised keys or governance.
ExchangeIssuance.issueSetForExactToken read component and unit data for a quote and later reused it after attacker-controlled hooks could mutate valuation state. This time-of-check/time-of-use gap let a malicious Valuer inflate the position multiplier and caused excess asset transfers.
How it happened
The attacker deployed a malicious SetToken, manager hook, and Valuer, then used the pre-issue hook to inflate the SetToken valuation before the issuance flow transferred assets.
Protocol details
Evidence
Understand the attack patterns
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