Balancer V2 Loses $128 Million in Major DeFi Hack

On November 3, 2025, the decentralized finance platform Balancer V2 was exploited for over $128 million, including significant amounts of WETH, osETH, and wstETH. The attack exploited a flaw in the "manageUserBalance" function, where faulty access checks allowed unauthorized withdrawals, amplified by hackers manipulating pool prices through malicious contracts and rounding errors.

The exploit affected multiple blockchains, with Ethereum suffering the largest loss ($99 million), and also impacted Balancer forks like Beets Finance. In a controversial move, Berachain validators halted their network to execute a hard fork to protect funds. This incident is particularly alarming as Balancer V2 had undergone over ten security audits between 2021 and 2023, leading experts to question the sufficiency of static audits and call for continuous, real-time monitoring.

The market reacted with the BAL token dropping 11.1% and Total Value Locked (TVL) nearly halving. Balancer offered the hacker a 20% bounty to return the funds within 48 hours, while some affected protocols, like StakeWise, managed to recover a portion of the stolen assets. The sophisticated nature of the attack bears similarities to state-sponsored hacking groups, fitting into a broader trend of over $2.2 billion in crypto theft in the first half of 2025.

(Source：Brave New Coin)