2018-05-16 Efail Vulnerability Affects Encrypted Mails
Recently, a severe vulnerability called "Efail" was detected that affects Thunderbird with S/MIME and Enigmail. The vulnerability is such that you could reveal decrypted message data to a malicious third party by just reading an email, without noticing it.
We have implemented several fixes to avoid this from happening. However, Thunderbird is still vulnerable today. We therefore recommend that you:
update to Enigmail 2.0.4 as soon as possible. view messages as "Simple HTML". This will block sending anything unintentionally to an external server. To switch to the "Simple HTML" view, go to menu View > Message Body As > Simple HTML
You better remove this build from updates-testing. Right now a lot of people want to update
dhcp-client and if they add a
--enablerepo=updates-testing to their dnf command thinking they want the latest version, they actually get an older one (the latest that fixes the flaw has been pushed to stable already)
That likely means that the mirror you are connecting to does not yet have the packages (still -300, and you can't install the same kernel a second time). You can try..
sudo dnf clean all && sudo dnf --enablerepo=updates-testing update kernel*
or just wait a couple of hours.