The problem is that you don't know which files are affected if there is no patch file in the bugtracker. You could try to find the associated cvs commit using Jeff's cvs browser:
http://xarg.net/tools/cvs/. If it's a simple fix then you might be able to get a diff from there and apply it to your OpenACS installation, but if it's more complex then it maybe depends on other upgrades, which might depend on even further changes etc. etc. so you'd be better off waiting for a new release.
