Per Cisco Security Advisory ID: cisco-sa-20090727-wlc there appears to a lot of security vulnerabilities. It is recommending that upgrade my controllers to 126.96.36.199 which I have no problems in doing.
Question: Would I also need to upgrade my WCS software (firmware) as well; seeing as though the controller software will be a much newer version?
188.8.131.52 got released 4 days ago. There is actually no WCS version that was released after this, so there is no actual WCS version that will work 100% with this newer controller version.
If you must upgrade your controller to 184.108.40.206 you can do so, but you will loose managing ability from WCS until there is a new Maintenance Release of 4.2.x, 5.2.x or 6.0.x.
I suggest that you wait if the security advisory is not applicable to your environment.