CentOS 6.2 (and hence RHEL 6.2, the current version) is on sudo-1.7.4p5.
Fedora compiles everything with -DFORTIFY_SOURCE which means this still crashes, but is not (thought to be) vulnerable. In any case there is an update available for Fedora right now. https://admin.fedoraproject.org/updates/sudo-1.8.3p1-2.fc16