Google Calendar users must be careful about what they add as a latest discovery of a bug in the app reveals that the event can be inadvertently shared with others.  One of the most useful apps in Google Mobile Service, the Calendar app is widely used by different people to mark important private and official tasks. But a bug in the app is inviting people whose names or email addresses are mentioned in the event.

The malfunction was mentioned by developer Terence Eden in his blog.  He explains how the calendar app on Google is sending out invites to other users whose names or email addresses are mentioned in the subject of the event. Other users won't receive an email notification about the event, but will get a pop-up reminder.

Like Eden points out, his wife added a reminder on Google Calendar to alert her about discussing her pay raise with her boss. But the actual problem came in when she made the mistake of adding her boss' email address in her note. Google notified her boss about the personal note, which she learnt after her boss sent her a "Meeting Accepted" email.

This bug can put users in awkward situations if the reminder is set for your eyes only. Eden found that the event created on an Android phone did not trigger a meeting request, but if a user added a non-Gmail email address to the note, chances were that the notification was sent to that user. Not just that, if a user tried deleting an entry on Google Calendar, then a cancellation notification will be pushed to the person mentioned in the note, even if the user was not originally invited, according to Eden.

"There are two main risks here - the user could expose her private Gmail account and associated Google+ data, and she could also reveal her private thoughts and feelings," Eden wrote in hisblog. "Google really needs to work harder at protecting the privacy of its users."

Google responded to Eden saying the issue had minimal impact on the security of its users, and it needed no additional attention and that he does not qualify for the bug bounty reward.

Later, in a statement sent to The Verge, Google said that it was actively working to fix the issue with its Calendar app.