Once we got an urgent requirement to add double hashing the password in a web application. It had to go to the production ASAP. The developer which was working on it, added 2 alerts in Javascript to display entered password and encrypted password. Finally change was ready to deploy but in hurry she forgot to remove the alerts. In rush and excitement, that change was shipped to the production. The alert says 'your password is 123', 'your password is xyz'.

After some time got phone calls from users and manager. Manager said, 'how the hell our application got HACKED? If anything happens to..........'. To cut it short, he was furious. We knew exact reason and solution. Didn't take couple of minutes to resolve this issue.

But it was funny mistake and that released that days pressure off.