Across V3 is a cross chain optimistic bridge. Users deposit assets on an origin chain, and relayers compete to immediately fulfill the request on the destination chain. At a slower pace, the protocol uses UMA’s Optimistic Oracle to validate relays, and LP funds are used to refund the relayers. On January 28th, 2025, deadrose and I discovered a High Severity vulnerability in the protocol that would allow the full value of certain transactions to be stolen from users by malicious relayers. To u...