This paper addresses a problem of violating the member accessibility of a class in C++, which is not detected as an error by existing C++ compilers. The member access specifiers can be used to specify member accessibility. The C++ uses a private or protected specifier for specifying the members which cannot be accessed from outside of an object. However, the private or protected members can be accessed from outside of that object by the pointer arithmetic in C++. We show some violating examples that cannot be detected by existing C++ compilers. The contribution of this paper is to discover and define the new problem of the member accessibility.