According to TechFlow, Offchain Labs, the development team behind Arbitrum, announced two serious vulnerabilities in the OP Stack fraud proof. On March 22, the team disclosed to the OP Labs team two serious security vulnerabilities it found on the Optimism testnet. These vulnerabilities exist in the Optimism fraud proof system deployed by OP Labs. Offchain Labs provided the OP Labs team with demonstration exploit code for the attack.

On March 25, OP Labs confirmed the validity of the two issues, and the two parties coordinated the vulnerability disclosure time, and finally disclosed the relevant vulnerabilities for the first time today.