The box is up and is most likely functioning properly. I would have the box power cycled when you will not have any disruption to users, power cycling the box is the only way to free up the memory that is not being released . I would then monitor the box for additional occurances of this problem , It may only be a one time event. An IOS upgrade may open up a whole new can of worms.
If this is a 2600 0r 3600 series router you can alloacate additional memory to the processor pool by using the ' memory-size iomem xx ' command
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...