|If the CDs aren't too badly scratched you can use toothpaste to try and buff out the scratches / scuffs. |
There's also the option of going to a DVD rental store (if such a thing still exists). Most of them have professional buffing machines that can restore CDs.
If you are successful best practice would be to immediately create a couple of backups in case the CD fails again.
Just done a quick browse online and came across this article which might be helpful: