I assume that you can get into the game, so I believe if you send a bug report from within that game that the password can be reset.
If the game has started, keep this in mind:
Sasri wrote:
Players will no longer be able to join running games after a certain amount of days. This varies between 7 and 10 days depending on the map. This might change in the future still and can also be applied differently to event maps. We made this change to limit account pushing, multi account and wolfpacking.
