There is a security vulnerability present in OctoPrint version 1.3.0rc1 through.5 that puts your instance at risk if it is. accessible directly via the internet or another untrusted network, e.g. through a port forward in your router. If you still havent updated to. October 3.6, please update ASAP. The issue allows unprivileged admin access to your instance over the network, bypassing access control. The vulnerability was discovered by myself and nobody else has discovered it and Im not aware of anyone exploiting it.”]
Source: https://octoprint.org/blog/2018/03/15/security-issue-update-to-1.3.6/