I assume it is 1,000 high with respect to the profile.
That would be about 5,000 AGL. I understand the mode used was V/S? Like in an above glideslope capture?
In every mode there is a form of protection from overspeeding. That shouldn't happen. In V/S mode, the target will be reduced to remain below VFE. In OP DES the A/THR will revert to SPEED and keep speed below VFE. If you are hand flying and ignoring the FD the A/THR will also revert to SPEED.
If speed was exceeded something was really wrong.
It happens, sometimes, that a pilot first tries to steepen the gradient by means of descending in OP DES at high speed (that is, close to VFE) then once he gets LOC*, he arms/checks G/S is blue and sets the FCU ALT above actual altitude, thus inducing a reversion to V/S (and therefore SPEED). The problem is that selected speed target remains high and in case your actual speed is less than target, because you were still accelerating to it in OP DES at the time, as soon as SPEED engages the engines will spool up. It is fixed by reducing the speed then checking/activating approach phase and managing speed. But if you don't, there should be no overspeed, though. V/S mode has a protection.