Balancer V1 Legacy Pool Rounding Error

What happened

An attacker exploited a rounding error in an unmaintained legacy Balancer V1 pool on Ethereum on 30 August 2026. DefiLlama, filing it under the Balancer parent protocol, records the loss at $234,000 and classifies it as a token and share accounting rounding error.

The interest here is the age of the code rather than the size of the loss: Balancer V1 dates from 2020 and the pool was no longer maintained, so this is a reminder that a deprecated contract keeps running and keeps holding money. The precise mechanics circulating elsewhere, and a claim that Balancer Labs dissolved as a company in March 2026, could not be confirmed against a source that opened, and are not asserted here.