Balancer v2’s Overlooked Guard

Balancer v2 Vaults saw rapid outflows from multiple pools on several chains, with early loss estimates ranging from about $70M to $117M while responders were still isolating the impact. Researchers including kebabsec noted that in the suspicious calls ops.sender equaled msg.sender, and suggested that a state change during withdrawal proxy setup was the root cause. OKcontract, which is building Chainwall Protocol, cites 2025 loss data dominated by social engineering, cloud keys and front-end tampering to argue that defenses must span both code and operations.