Documents operations, in this case "drawing", could be manipulated to contain invalid data types, possibly script code. Script code could b…

Documents operations, in this case "drawing", could be manipulated to contain invalid data types, possibly script code. Script code could be injected to an operation that would be executed for users that are actively collaborating on the same document. Operation data exchanged between collaborating parties does now gets checked for validity to avoid code execution. No publicly available exploits are known.