hotfix
A hotfix is code (sometimes called a patch) that fixes a bug in a product. Users of the products may be notified by e-mail or obtain information about current hotfixes at a software vendor's Web site and download the hotfixes they wish to apply. Hotfixes are sometimes packaged as a set of fixes called a combined hotfix or a service pack.
Quick fix engineering (QFE) is a newer Microsoft term for a hotfix.