Arbitrum Halts New Stylus Contracts Amid Security Concerns
The Arbitrum security committee has implemented an emergency upgrade on October 2nd, US Eastern Time, at 11:30 AM, affecting both Arbitrum One and Nova. This upgrade temporarily halts the activation of all new Stylus contracts on these chains.
Stylus is a framework that allows developers to write smart contracts in languages like Rust and C++ while maintaining compatibility with the Ethereum Virtual Machine (EVM). However, this upgrade specifically targets hand-written WebAssembly (WASM) programs that have not been compiled using the standard Stylus toolchain or patched by the current version of ArbOS.
The security committee increased the gas required for activation to its theoretical limit, making it economically impractical for new contracts to be activated. Existing Stylus contracts remain unaffected and can continue executing and renewing as usual. Solidity contract deployments and executions are also not impacted.
Additionally, a new BoLD protection mechanism has been added to the Arbitrum One dispute system. This allows anyone to pause Arbitrum One's settlement with Ethereum when there are two conflicting and accepted answers in the same dispute step.