Uninitialized pointer field

The pointer field will point to an arbitrary memory location, any attempt to write may cause corruption. A pointer field is not initialized in the constructor
/src/mongo/db/exec/express/express_plan.h:1180: UNINIT_CTOR 155587 Class member declaration for "_stats".
/src/mongo/db/exec/express/express_plan.h:1150: UNINIT_CTOR 155587 Non-static class member "_stats" is not initialized in this constructor nor in any functions that it calls.