Keep your application’s dependencies up to date.
Make sure you upgrade your package dependencies
to keep the dependencies up to date.
Avoid pinning to specific versions
for your dependencies and, if you do, make sure you check
periodically to see if your dependencies have had security updates,
and update the pin accordingly.

Keep your copy of Flutter up to date.
Private, customized versions of Flutter tend
to fall behind the current version and might not
include important security fixes and enhancements.
Instead, routinely update your copy of Flutter.
If you’re making changes to improve Flutter,
be sure to update your fork and consider sharing your
changes with the community.