Lost my wallet password. Is there anything I can do? I lost my bitcoin wallet password, it was stored on a USB and I've lost the usb. Luckily I have a backup of my wallet. Are there any way possible I can get my coins back? Is there a bitcoin wallet cracker available?

Also the version was bitcoin-qt 0.50, I've heard there may be vulnerabilities in the code that could be able to get my coins back?
Are you saying you still have a backup of the wallet.dat file ? If so, did you secured your bitcoin-qt 0.50 with a passphrase ? If not, install the latest version of bitcoin-qt, start the program once, exit it after it has appeared on your screen, and replace the wallet.dat file that has been created with the backup. Then restart bitcoin-qt and wait till the blockchain has been completely downloaded. This could take hours, but your BTC should appear again.