VULNERABILITY DETAILS
I had logged out of my Chrome session earlier in the day using the "Exit and Childlock Feature" so my wife could log in with her own account. When I got home there were YouTube notifications, generated by Chrome, waiting for me (Bottom right hand corner). My wife was still logged into her account on Chrome, but the notifications were from Youtube channels I follow. I signed her out using the "Exit and Childlock" feature, which got me back to the logon screen. I then accidentally clicked on one of the notifications, which then opened Chrome and loaded the youtube video - but also my previous tabs, which included Inbox. This all happened before I could actually use the User Logon window to sign in. 

I thought that it might have launched the tabs, but would prompt me to sign into the pages - but it didn't, just loaded my emails.

In summary: YouTube notifications kept coming through Chrome, ignoring the fact that I had used the "Exit and Childlock" feature to sign out earlier in the day, and then proceeded to launch my previous session without prompting for credentials.

VERSION
Chrome Version: Version 59.0.3071.115 (Official Build) (64-bit) Stable
Operating System: Windows 10 Version 1607 (OS Build 14393.1358)

REPRODUCTION CASE
Please see attached.
 

Deleted: 2017-07-03 19_08_32-(44) Dragonball FighterZ Brings the Anime to Life - YouTube.png 960 KB

	2017-07-03 19_08_32-(44) Dragonball FighterZ Brings the Anime to Life - YouTube.png 960 KB View Download