If you mean edit the SWF directly, then no. But why would you want to?
Because the answer is yes, if you mean edit the FLA and republish the SWF from it.
If you can do that, why would you want to edit the SWF directly?
It would be like knowing you can take the wheels off a car to change the tyres, but insisting on doing it with them still on the car More difficult than needs be.