Fun fact, there was a universal XSS vulnerability on google (including search, support, accounts, cloud, etc) found just last week [0]. I'd say it's always just a matter of time. That doesn't mean they don't have everything in order, but securing everything as much as possible is half the battle. The other half is a solid response when things do happen, which we will now see in how Docker handles this situation.
[0] https://twitter.com/WHHackersBR/status/1118393568656334850