Offchain Labs, the development team behind Arbitrum, has disclosed two serious vulnerabilities in the OP Stack fraud proof system on the X platform. It is reported that on March 22, the team disclosed two serious security vulnerabilities it discovered on the Optimism testnet to the OP Labs team. These vulnerabilities exist in the Optimism fraud proof system deployed by OP Labs. Offchain Labs provided demonstration exploit code for the attacks to the OP Labs team. On March 25th, OP Labs confirmed the validity of these two issues, coordinated the disclosure time with the other party, and finally disclosed the relevant vulnerabilities for the first time today.