Berachain distributes hard fork binary to address Balancer V2 exploit

The Berachain Foundation announced progress on an emergency hard fork initiated to address a vulnerability in its decentralized exchange, BEX, stemming from a broader exploit that targeted Balancer V2 pools and forks across multiple chains.

In a statement posted on X late Monday, the foundation said that the hard fork binary has been distributed to validators, many of whom have completed upgrades. The binary prevents addresses moving exploited tokens outside of the network and further attacks on Berachain.

"Prior to going live and producing blocks once again, we'd like to ensure that core infrastructure partners necessary for chain operations ... have updated their RPCs, so at this point they will be our main blocker to resuming liveness," the foundation wrote in the announcement.

On Nov. 3, Berachain validators halted the network after Balancer V2 was hit with an exploit that drained roughly $128 million on pools across multiple chains, including Ethereum, Arbitrum, Base and Polygon.

Blockchain analytics firm Nansen attributed the incident to a faulty access-control mechanism, enabling an attacker to fabricate fees and convert them into withdrawable real assets via a pair of Ethereum transactions executed within 90 seconds.

This exploit exposed a vulnerability in BEX, a fork of Balancer V2, and led to around $12 million being drained primarily from BEX's "Ethena/Honey tripool," the team said.

"Given that it affected non-native assets (not just BERA), the rollback/rollforward involves more than a simple hardfork, hence the halt as a full solution is finalized," the foundation previously said.

Berachain Foundation said it is in conversation with the current holder of the drained funds, who is an MEV bot operator that has indicated that he is a "white hat" actor and willing to pre-sign transactions for their return once the chain resumes operations.

"Once the chain is live again, we will also provide a rundown of the various safety measures implemented across the BEX, other core apps, and Berachain as a whole," the foundation wrote. "The team will also provide further information on future facing plans for BEX and any other expected second order effects from the last 24 hours."

The decision to halt the network drew measured support from industry observers. Smokey The Bera, co-founder of Berachain, described the action as "contentious but necessary" to safeguard user deposits. On-chain investigator ZachXBT also endorsed the pause, stating it as a move prioritizing users.