But managers at the company chose not to go public with the bug, however, because they anxious that it would invite scrutiny from regulators, particularly in the wake of Facebook's recent security missteps.
The incident also marks the beginning of the end for Google+, which the company plans to shut down over the next year. The search giant states that it wasn't able to maintain "a successful Google+ product that meets consumers' expectations".
News of the bug sent shares of Google's parent company, Alphabet, down as much as 2.2 percent to $1,142.43 on Monday afternoon.
According to the Google+ Profile API documentation, profile fields can store a treasure trove of sensitive user details such as such as name, email address, occupation, gender, age, nickname, birthday, just to name a few.
For Google, a data privacy reckoning may finally come as a result of a service that it admits nearly no one uses much anymore.
Per WSJ, a "software glitch" allowed user data to be potentially exposed to unwanted eyes from 2015 all the way through March 2018 when Google learned about it.
Google has recently been at the center of a number of privacy breaches.
The Google+ data leak bug was found as part of "Project Strobe", a root-and-branch review of what data developers could access from Google accounts, and Android devices. Even in that short amount of time, Google's audit found that almost half a million Google+ accounts could have been affected in just 14 days' worth of analysis.
The Wall Street Journal reported earlier that Google opted not to disclose the security issue due to fears of regulatory scrutiny, citing unnamed sources and a memo prepared by Google's legal and policy staff for senior executives.
The tech firm kept quiet for months about a security flaw that gave third-party apps access to private information on the Google+ social network. Third-party SMS apps will still be allowed, but they can only access this data if the user sets the app as their default for text messaging.
Google has been trying to gain a foothold in social networking for years, going all the way back to the tragically flawed Google Buzz in 2010.
It also announced other security features. Somehow, the intimate data of the first user would be included in the collection profile. Google was hammered again a month later, when the Associated Press revealed the company was tracking users' locations even after they'd turned off their phones' location history setting. They'll further limit these permissions by removing contact interaction data for the Android Contacts API.
Nikki Haley thinks Jared Kushner is a ‘hidden genius’
He told reporters in the Oval Office that she would be leaving the post at the end of the year after doing "an incredible job". Haley stayed coy on her reasons for quitting, saying only that it was "important to understand when it's time to stand aside".
Here’s Our First Look at Ruby Rose as Batwoman
It's pretty chic, which isn't surprising considering it's been designed by Oscar victor Colleen Atwood . Rose was announced as the new Batwoman in August to both celebration and some social media backlash.
Osaka slumps against Sevastova in Beijing
The Argentine top seed Del Potro will face either Britain's fifth seed Kyle Edmund or unseeded Nikoloz Basilashvili of Georgia. Wozniacki claimed her first China Open title in 2010 when she jumped to top the WTA rankings for the first time.
Israel PM's wife goes on trial in delivery meals case
Netanyahu appeared before the Jerusalem's magistrates court but made no remarks before the press was asked to leave. Her husband, Benjamin Netanyahu, is himself embroiled in a series of corruption investigations .