Yes, that is why the older datasheets and application notes say to use a regular electrolytic on input and output, to damp down that ringing, or use solid tantalum. Series resistor with the capacitor, and likely also a series resistor in the power line, value and wattage so that the highest power draw and lowest input voltage means regulator input is 8V, and nearest lower value in the appropriate power rating, will also help, and also adds to needing a smaller heatsink, as all power is dropped in the resistor.