Arbitrum blocks new Stylus activations over AI-assisted attacks

Arbitrum's Security Council temporarily blocked new Stylus program activations on Arbitrum One and Nova on October 2. The Foundation attributes the precaution to increasingly sophisticated AI-assisted attacks involving specially crafted WebAssembly programs.

Already-active Stylus programs continue until expiration. Ordinary Solidity and EVM applications are unaffected. Activation makes stored Stylus code executable, so the restriction is not a complete network shutdown.

The Council also added a separate safeguard for BoLD's proof process on Arbitrum One. If conflicting answers are accepted as valid, the mechanism can halt settlement to Ethereum. Unconfirmed withdrawals would then wait; installing the safeguard does not itself trigger that pause.

The Foundation says known Stylus problems mainly threaten continued operation and that no attack enabling theft of user funds has been discovered. Its report documents a security response to AI-assisted attacks, not an AI system acting beyond its assigned task.