Base vault: ~$6M wstETH drained after Safe whitelist change
04 Oct 2026: an unnamed OpenZeppelin vault on Base lost its whole wstETH position (about 1,783 wstETH, ~$6M).
The vault's anonymous 3-of-7 Safe added a freshly deployed contract to the whitelist with three valid owner signatures; that contract pulled aBaswstETH and redeemed through Aave to wstETH.
Blockaid, PeckShield, CertiK, and ExVul independently flagged the drain. Firms agree Base and Aave core were not compromised. Root cause unconfirmed (stolen keys, mismatched signing UI, or insider still open).
About 1,001 wstETH entered the Base to Ethereum canonical withdrawal; remaining value stayed on Base in early 05 Oct reporting.
7M still exposed via aBasWETH collateral versus USDC/EURC debt, with no whitelist revocation seen in the first hours. No operator has named itself and no post-mortem is out.
Research snapshot from CryptoTimes, SigIntZero, PeckShield mirrors, and related press.
Update
Whitelist pulled and re-added in about one minute; deployer submitted both calls
06 Oct Grok window: ExVul timeline shows the owner Safe removed the attacker contract from the whitelist at 08:52 UTC and re-enabled it at 08:53 UTC, both with three valid signatures.
The first borrow followed about 70 seconds later.
An on-chain registry read says both admin transactions were submitted by the address that deployed the vault in Feb 2025, unlike earlier Safe activity from a different submitter.
That points at the operator signing or submission path. Stolen keys, a mismatched signing UI, or an insider are still all open.
No freeze, bounty, recovery, whitelist revocation, or named operator as of 06 Oct. About 1,001 wstETH in the canonical Base to Ethereum withdrawal is cited as claimable around 11 Oct.
Collateral still in the vault remains large versus Aave debt.
Update
Immunefi: whitelist design + no disclosure channel
07 Oct Grok window: Immunefi's Gonçalo Magalhães says once an address was on the whitelist, the vault let it pull assets without posting collateral.
Researchers had spotted that weakness about a week before the drain but had no clear way to report it to an anonymous operator.
TokenPost notes the Safe had gone about 25 days without a transaction before the whitelist change. 7M still cited in the vault.
About 1,001 wstETH in the Base to Ethereum withdrawal remains claimable around 11 Oct.
369 take
Three valid Safe signatures opened a whitelist and emptied the vault in minutes. Base and Aave were not the bug.
Pulse lesson for any multisig-run vault or adapter: treat signing UI and whitelist changes as the perimeter; prefer delay or guardian on admin paths that can empty the book.
Sources
- CryptoTimes. Base vault ~$6M after whitelist access
- SigIntZero. Signed whitelist drain reconstruction
- Bitcoin.com. Mystery 7-signer vault coverage
- TokenPost. ~$31.7M still at risk notes
- iTokenly. Registry read on deployer-submitted whitelist txs
- Startup Fortune. Whitelist added twice in one minute
- crypto.news. Immunefi disclosure-gap comments
- TokenPost. Follow-up notes