Pallets Werkzeug before 0.15.3, when used with Docker, has insufficient debugger PIN randomness because Docker containers share the same machine id.
lists.opensuse.org/opensuse-security-announce/2019-09/msg00034.html
lists.opensuse.org/opensuse-security-announce/2019-09/msg00047.html
github.com/pallets/werkzeug/blob/7fef41b120327d3912fbe12fb64f1951496fcf3e/src/werkzeug/debug/__init__.py#L168
github.com/pallets/werkzeug/commit/00bc43b1672e662e5e3b8cecd79e67fc968fa246
palletsprojects.com/blog/werkzeug-0-15-3-released/