Beanstalk

On April 17, 2022, Beanstalk Farms — an algorithmic, credit-based stablecoin protocol on Ethereum — lost $182 million to a governance exploit. Blockchain security firm PeckShield flagged the attack the same day (CoinDesk). The attack took a single transaction and exploited the protocol's voting logic rather than a smart contract bug.

How the attack worked

Voting power in Beanstalk was based on how much Stalk (its governance token) an address held at the moment of voting — with no snapshot from an earlier block and no lock-up period. That design choice was the actual entry point.

• The attacker took out a chain of flash loans — uncollateralized loans that must be borrowed and repaid within a single transaction — totaling roughly $1 billion in DAI, USDC and USDT across Aave, Uniswap and SushiSwap (Halborn).
• That capital was deposited into Curve pools holding BEAN, instantly giving the attacker a supermajority of Stalk voting power.
• With that supermajority, the attacker pushed a malicious proposal through the emergencyCommit function — a mechanism meant for urgent decisions once a supermajority was reached, which bypassed the protocol's normal roughly 24-hour execution delay.
• The proposal transferred the protocol's reserves — BEAN3CRV LP tokens and other assets — to the attacker's address.
• The attacker withdrew the liquidity, repaid every flash loan within the same transaction, and walked away with 24,830 ETH and 36 million BEAN — a net take of roughly $76–80 million. The gap between that figure and the $182 million headline number reflects the pre-attack value of protocol-owned assets and of BEAN itself, both of which collapsed once the treasury was drained.

Sources agree on the mechanics and describe it as a flash-loan governance attack; they diverge only on the exact share of votes captured (estimates range from roughly two-thirds to about 79%). Nobody disputes the core method — borrowing enough capital for one block to seize control of a vote.

What happened next

The attacker laundered the proceeds through Tornado Cash and sent $250,000 of it to a Ukraine relief donation address (CoinDesk) — none of the stolen funds were ever returned by the attacker.

Beanstalk received no compensation from the exploiter. Instead, in June 2022 the team launched a “Barn Raise” campaign, selling 77 million Fertilizer tokens at $1 each — effectively a loan against future BEAN issuance, with an implied return of up to 500% (CoinDesk). This was new debt taken on by the protocol and its community, not recovered stolen money. After two independent audits and a shift of governance to a nine-member community multisig — pending a redesigned, flash-loan-resistant voting mechanism — Beanstalk unpaused on August 6, 2022, following a vote in which holders of more than 99% of Stalk approved the relaunch (The Block).

What this means

• Any protocol that ties voting power to an instantaneous token balance rather than a prior snapshot or a locked, vested position is exposed to the same pattern — this applies to on-chain governance generally, not just stablecoins.
• A visible warning sign: if a governance token trades freely on DEXs with enough liquidity to support a large flash loan, and voting has no snapshot or timelock protection, control of the protocol can effectively be rented for a single block.
• “Emergency” execution paths that skip the normal delay are a double-edged design choice: the same emergencyCommit function built for crisis response became the attack's execution vector.
• The incident became the reference case for flash-loan governance attacks; it pushed wider DAO practice toward snapshotting voting power at proposal creation and enforcing a mandatory timelock between a vote passing and its execution.