You can specify a version
dnf install emacs-25.1-3
As an example on Fedora25.
If there are dependency issues, try one of the following:
dnf check-update; dnf upgrade --best
Or, if you'd like, you can tell it to "allow erasing" other packages. This is destructive, obviously.
dnf upgrade --allowerasing
Finally, you also have an option to upgrade to a specific version; though, this appears to be an obsolete option.
From the man-pages:
dnf [options] repository-packages upgrade-to
Update packages to the specified versions that are available in the repository. Upgrade-to is deprecated alias for the upgrade
If you notice, you used the
update option, rather than
upgrade in your initial command.
Please take a look at the Fedora Admin Guide: Software Management as well as the DNF Documentation.