As promised, we released a new version yesterday: Release Mautic Community 3.2.4 · mautic/mautic · GitHub
Versions 3.2.4 and higher aren’t affected by this bug. But if you’re currently running a version between 3.2.0 and 3.2.3, then you can apply this workaround to get to 3.2.4 (make sure to cd into your Mautic folder first, e.g. /var/www/html):
wget https://github.com/mautic/mautic/releases/download/3.2.4/3.2.4-update.zip
php bin/console mautic:update:apply --update-package=3.2.4-update.zip
php bin/console mautic:update:apply --finish