Calendars listing with graph return inconsistent results.

Question

Hello,

I'm having issues with the graph endpoint to fetch the calendar of a user with Graph.
The issue is linked to the shared calendars of the organization.

Here is the setup we use :

• Connect to outlook
• Subscribe to the calendars of some colleagues with the "add from directory" feature

From there we're having some weird results.
When we call for this endpoint : https://graph.microsoft.com/v1.0/me/calendars some of us are receiving only our own calendars. Some of us are receiving their own calendars AND some colleague calendars.

But even in this second case, they are not receiving all of their colleague calendars, just a few of them.

Here are some additionnal data we gathered with a few tests :

• The calendars don't "blink". Once you have it through the endpoint, you have it every time
• There is no logic on which calendars you received as two person with the same subscriptions won't receive the same calendars

It's important to note that our token ONLY have Calendars.ReadWrite and NOT Calendars.Read.Shared

I'm a bit lost with all this.
It looks like an issue to me. No one should receive some shared calendar as we don't have the permission on the token right ? And even if we should receive them, we should receive all of them, not just some random ones.

Thanks for your help :)

Answer 1

Hello Jocelyn Dubois,

Thank you for contacting Microsoft Support!

As you mentioned, your token has Calendars.ReadWrite but not Calendars.Read.Shared. This means you should only be able to access your own calendars and not shared ones.

I have followed the same steps provided by you and not getting calendars of other users in the Graph API response.

I would recommend you raise a support case with Microsoft Graph, a Support Engineer will be able to look into this issue and assist you better. You can raise support ticket from New support request - Microsoft Entra admin center or https://admin.microsoft.com/#/support/requests.

Hope this helps.

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