No, installing packages from the wrong distribution version is not safe. Despite that people seem to do it all the time (and usually break their systems in amusing ways). In particular glibc is the most critical package on the system; everything is built against it, and if its ABI is changed then everything would have to be rebuilt against it. You should not expect software built against one version of glibc to work when another version is present.
And anyway, this vulnerability has been around for over 14 years, and despite all the yelling and screaming about it, it requires a fairly narrow set of circumstances to exploit. Waiting a day or two for a proper patch isn't likely to be a problem.