https://medium.com/@cipherpunk/efail-a-postmortem-4bef2cea4c08 [medium.com]
https://admin.hostpoint.ch/pipermail/enigmail-users_enigmail.net/2018-May/004995.html [hostpoint.ch]
Writing just for himself -- not for GnuPG and not for Enigmail and definitely not for his employer -- Robert J Hansen, an Enigmail developer and GnuPG volunteer, put together a postmortem on Efail.