Where to report a security issue?

I have a relatively fresh Ubuntu 18.04 LTS installation on a Lenovo ThinkPad T580. When I put the computer in standby mode, it enters standby mode. When I wake it up again, the screen as it looked when I entered standby mode flashes briefly before the lock screen is shown. I think you have at least half a second to look at my stuff before the view changes to the lock screen. IMHO this is a security issue. Where should I report this?

Best regards,


I think that a bug against the gdm3 package would be a proper measure.

Please install all updates and then restart your computer. That issue might already be fixed.