(especially of a computer routine or program) not provided with a patch.
Example sentencesExamples
A new Windows worm has been hitting unpatched Windows 2000 computers en masse - and causing blushes at several media organisations along the way.
If you attach a new, unpatched and unprotected computer to the internet then it can easily be under the control of hackers within a matter of minutes.
They might have cleaner computers come fall, but they're still vulnerable because their operating systems tend to be unpatched and their antivirus software out-of-date.
The Witty worm started spreading in March 2004, infecting unpatched computer systems and appliances running security gateway software from network protection firm Internet Security Systems.
That's it really - no firewall misconfigurations, unpatched operating system problems or even a Microsoft Internet Information Server problem in sight.