https://koji.fedoraproject.org/koji/buildinfo?buildID=1027072

electrum is already on fedora.

please download the sources here, write a patch and file a pull request.

https://src.fedoraproject.org/rpms/electrum

I think it's fair to have this open against the electrum package, though a patch against the existing spec would be more useful than a whole new spec.  I did have a conversation on IRC recently with someone who might have been caravel about this, but I only suggested opening a bug against electrum, not opening a whole new review request.

Hopefully the current electrum maintainer will see fit to either update the package (which will also deal with the open security issue) or request that caravel be sponsored so that they can be made a maintainer and perform the update.  That request would be made via https://pagure.io/packager-sponsors.

I think sending a pull request in https://src.fedoraproject.org/rpms/electrum doesn't require special privileges, probably only a fas account, am I right ?

Well, it's complicated because you can't fork packages (or maybe you can fork but can't commit to the fork) if you aren't already a packager.  So caravel would have to send a remote pull request, which is fine but not as "automatic" and to be honest I don't have any idea how to do it.

I did some remote pull request

fedpkg clone package

or 

git clone src.fedoraproject.org/rpms/package


then make changes

create a empty git repo on github

git remote add github http://github-repo-address.

git commit 

git push github

file the remote pull request and point the github repo address.

This bug appears to have been reported against 'rawhide' during the Fedora 28 development cycle.
Changing version to '28'.

Electrum 3.0.6 have been pushed to stable