This sounds like there is a drain fault which is responsible for draining water in the sump.
In some cases the filter which is in the middle of the tray can be come blocked, and its worth removing that and giving it a good clean.
If that is clean the next step is to switch the appliance off at the wall, then use a cup or small bucket to remove the water, and lift the metal cover which the filter slots in to up, which exposes the sump, this remove all the water from this void and inspect the pump on the side to see if the blades will spin freely and if anything is tangled around it.
Once complete, put the sump cover and filter back in place, and run the dishwasher on a rinse cycle, and see if water starts to drain away as normal, if it doesnt this suggests a fault with the drain pump.
In terms of concerns around a flood, there is a flood sensor in the dishwasher, which if water reaches a certain point it will cut off the inlet, so no more water will come in.
Please let me know how you get on.