Your question is completely meaningless. Try and follow along. High impedance means no current flow at any voltage. No current flow means that an external driving source can take the high impedance pin to any voltage the driving source is capable of. This includes voltages that will cause the input protection diodes to breakdown. This won't happen if the driving source is between Vcc and Ground for the chip with the high impedance input.
With respect to Ground the high impedance pin can have any voltage that is placed upon it.