Ubuntu developers have stated in the official mailing list of the distribution that Linux Mint is a vulnerable system and people shouldn't do online banking on it.
A third-party developer had asked for help to build an Ubuntu MATE Remix based on Ubuntu 14.04, and people wondered what the point was when Linux Mint already featured such a desktop environment.
One of the Ubuntu developers, Oliver Grawert, pointed out that Linux Mint maintainers have a series of packages that they will never upgrade, making the system vulnerable to attacks.
“This is the list of packages it will never update, instead of just integrating changes properly with the packages in the ubuntu archive they instead suppress doing (security) updates at all for them.”
“I would say forcefully keeping a vulnerable kernel browser or xorg in place instead of allowing the provided security updates to be installer makes it a vulnerable system, yes. I personally wouldn't do online banking with it ;)” said Oliver Grawert.
His opinion was also shared by other Ubuntu developers who were participating in the discussion.