FlashLoopAdapter Exploit Drains $305K From Two Aave-Linked Safes

A custom Safe wallet module built to automate leveraged Aave v3 positions was exploited on October 1, draining an estimated $305,000 from two wallets on Ethereum, according to Coincentral. The module, FlashLoopAdapter, opens and closes looping strategies for Safes that have enabled it, and security researchers say its caller authentication, not Aave’s lending code, was the weak point.

Defimon Alerts flagged the incident at 15:08:57 UTC on October 1, describing the loss at $305,000 and classifying the cause as an access-control failure. The Block reported that SlowMist, a second security firm, put the figure at roughly 114.09 ETH, or about $310,000, and said the attacker forged Safe authentication before repaying debt and unlocking collateral.

Key facts

• The exploit targeted FlashLoopAdapter, a Safe module for opening and closing leveraged Aave v3 loops, and was detected by Defimon Alerts on October 1, 2026.
• Two Safe wallets were hit: one lost about 1,306.48 weETH and a second lost roughly 6.4 weETH through the same vulnerable module.
• The attacker repaid approximately 1,335 WETH of Aave debt using a WETH flash loan from Morpho, according to Defimon Alerts.
• Defimon Alerts estimated the loss at about $305,000 with roughly 114 ETH retained; SlowMist estimated about 114.09 ETH, or $310,000.
• Aave founder Stani Kulechov said the contract was a third-party external adapter with zero effect on Aave v3.

How the access-control bypass worked

SlowMist traced the flaw to the adapter’s open() and close() functions. Rather than independently confirming the caller was a genuine Safe, the functions checked whether ISafe(msg.sender).isModuleEnabled(address(this)) returned true. An attacker could deploy a contract that answered that check affirmatively, then use the resulting execution path to reach wallets that had enabled the module. Defimon Alerts noted that checks during the callback did not block the transaction because the attacker’s contract was also acting as the flash liquidity provider.

A second function, _swap(), let the adapter make a raw call to a swap router using caller-supplied calldata. According to Crypto.news, the attacker pointed the router parameter at one of the victim Safes and set the calldata to invoke execTransactionFromModule, a Safe function that lets an enabled module execute a transaction. Because the victim Safe had already enabled FlashLoopAdapter, the call went through. Crypto.news identified the first Safe as 0xcfedf95a3653a128dfc2e4288758a1a1850d169f and the second as 0xe3b23e47df7cd85876ac6cb05bdb9d7cd5b28520, adding that both shared a single owner. SlowMist listed the attacker address as 0x42c2633438609881c8fBAb82414eb9A0c45F9353 and the adapter contract as 0x16bb8b912da187870c23ec6756bb3fad061283d8.

The transaction involved more than a straight transfer of idle assets. The flash loan supplied WETH to repay about 1,335 WETH of Aave debt on the larger Safe, which freed the collateral tied to its leveraged position. The attacker then pushed that Safe to withdraw roughly 1,306 weETH to an address under their control. An Etherscan entry for the first Safe showed the burning of about 1,306.48 variableDebtEthWETH tokens alongside the matching weETH withdrawal, with a gross transaction value of about $3.88 million. Defimon’s $305,000 estimate reflects the amount left after the flash loan and debt repayment were settled, not that gross figure.

Why it matters

The distinction between a protocol and the third-party modules attached to it is the practical takeaway here. Aave v3 kept running, and neither security alert nor Kulechov identified a flaw in its lending contracts; the route into user funds ran through a custom adapter that Safes had granted transaction-execution permission. Safe modules can execute transactions from a wallet without the standard owner approval flow each time, which is exactly what makes them useful for automating strategies and what makes their authentication logic worth scrutinising.

The pattern is not new. In September, an Ethereum Safe holding a leveraged Aave v3 position lost about 2,900 rsETH, worth roughly $7.8 million at the time, after weak authorization checks in an executor contract tied to an enabled Safe module; an MEV bot called Yoink front-ran the attacker’s own transaction and took the funds, and Kelp DAO paused the receiving address while stating its core contracts and rsETH backing were unaffected. Earlier in May, an exploit involving the SquidRouterModule drained between $3 million and $3.2 million from 86 Safes on Ethereum and Base, with Squid saying its main router contracts and user funds were untouched. Days after that, Gnosis Pay users were urged to withdraw funds over a flaw in its Zodiac delay module.

What to watch

The FlashLoopAdapter investigation remains open, and it is not yet confirmed whether other wallets or contracts were affected. Wallets that enabled the module, and any other Safes running custom adapters with similar authentication patterns, are the obvious places to look for follow-up disclosures.

Disclaimer: This article is for information only and is not investment, financial or trading advice. Cryptocurrency prices are highly volatile. Always do your own research.

Sources: CoinCentral, Crypto.news