https://motherboard.vice.com/en_us/article/evbvqj/bug-in-googles-bug-tracker-lets-researcher-access-list-of-companys-vulnerabilities

Google's platform to deal with bugs and unpatched vulnerabilities had a bug that allowed a security researcher to see a full list of known, unpatched vulnerabilities within Google, creating a kind of bug inception that could have led to more damaging hacks.

Alex Birsan, a security researcher, found three vulnerabilities inside the Google Issue Tracker, the company's internal platform where employees keep track of requested features or unpatched bugs in Google's products. The largest one of these was one that allowed him to access the internal platform at all. The company has quickly patched the bugs found by Birsan, and there's no evidence anyone else found the bugs and exploited them.