There is a security fix to ensure that EnableFlow is always properly
attributed.
This may be an issue if you see users maliciously using
Special:EnableFlow on pages that already exist.
It should be merged shortly, but in the meantime, you can download it
from Gerrit (
https://gerrit.wikimedia.org/r/#/c/333301/):
git fetch ssh://gerrit.wikimedia.org:29418/mediawiki/extensions/Flow
refs/changes/01/333301/1 && git checkout FETCH_HEAD
Matt Flaschen