**[Balancer Releases Preliminary Report on Attack Incident: Exploitation of Rounding Logic Error in Batch Swap Transactions]** Foresight News reports that Balancer has released a preliminary report on the vulnerability attack incident, stating that the composable stable pools of Balancer V2 were attacked on November 4 across multiple chains (including Ethereum, Base, Avalanche, Polygon, Arbitrum, etc.). The vulnerability originated from the rounding direction of the scaling function in EXACT_OUT swaps within the composable stable pools. When the scaling factor includes non-integer values (i.e., when token exchange rates are incorporated into the scaling factor), the function rounds down. Attackers exploited the incorrect rounding behavior in combination with the batch swap functionality to manipulate pool balances and extract value. This incident only affected the composable stable pools of Balancer V2, while Balancer V3 and other pool types were not impacted. The Balancer team, along with security partners and white-hat teams, acted swiftly to prevent the spread of the attack and recover some assets through measures such as Hypernative's automatic suspension, asset freezing, and white-hat intervention under the SEAL framework. StakeWise has recovered approximately 73.5% of the stolen osETH, while teams like BitFinding and Base MEV bot have also assisted in recovering some funds. Currently, Balancer is collaborating with partners such as SEAL and zeroShadow to conduct cross-chain tracking and asset recovery. The final verified losses and recovery data will be disclosed in a comprehensive technical review report.