This is just for the awareness to use HTTPS everywhere, even for outgoing links - where it's possible.
Treat this report with some salt, not as in hashes.
Some of the External Links on that Page redirects to HTTPS after click, but cookie is sent on the network before that.
See the Previous Reports: https://hackerone.com/reports/260591
See the Attached Image.
Best Regards, Anees Khan