Calendars.ReadWriteMicrosoft Graph permission · High risk
Allows the app to create, read, update, and delete events of all calendars without a signed-in user.
Application permission
High riskRead and write calendars in all mailboxes. Allows the app to create, read, update, and delete events of all calendars without a signed-in user.
| ID | ef54d2bf-783f-4e0f-bca1-3210c0444d99 |
|---|---|
| Consent | Always needs admin consent |
| Risk | As an application permission this reaches every user's data in the tenant, without anyone signed in. |
Delegated permission
Medium riskHave full access to user calendars . Allows the app to create, read, update, and delete events in user calendars.
| ID | 1ec239c2-d7c9-4623-a91a-a9775856bb36 |
|---|---|
| Consent | Users can consent, if your consent settings allow it |
| Risk | Reads or changes the signed-in user's content, limited to what that user can access. |
Least-privilege alternative
If the app only reads calendars, use Calendars.Read. For application permissions, limit mailboxes with Exchange Online RBAC for applications.
Grant it to an app
In the portal: App registrations › your app › API permissions › Add a permission › Microsoft Graph › Application permissions, then grant admin consent. Or with Graph PowerShell:
Connect-MgGraph -Scopes "Application.Read.All", "AppRoleAssignment.ReadWrite.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
$app = Get-MgServicePrincipal -Filter "appId eq '<your app's client id>'"
New-MgServicePrincipalAppRoleAssignment -ServicePrincipalId $app.Id `
-PrincipalId $app.Id -ResourceId $graph.Id -AppRoleId "ef54d2bf-783f-4e0f-bca1-3210c0444d99"Ask for it when signing in
Delegated permissions act as the signed-in user, so the app can never do more than that user can.
Connect-MgGraph -Scopes "Calendars.ReadWrite"Which apps already have it?
# Apps that hold Calendars.ReadWrite as an application permission
Connect-MgGraph -Scopes "Application.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgServicePrincipalAppRoleAssignedTo -ServicePrincipalId $graph.Id -All |
Where-Object AppRoleId -eq "ef54d2bf-783f-4e0f-bca1-3210c0444d99" |
Select-Object PrincipalDisplayName, PrincipalId, CreatedDateTime# Apps with delegated consent for Calendars.ReadWrite
Connect-MgGraph -Scopes "Application.Read.All", "Directory.Read.All"
$graph = Get-MgServicePrincipal -Filter "appId eq '00000003-0000-0000-c000-000000000000'"
Get-MgOauth2PermissionGrant -All |
Where-Object { $_.ResourceId -eq $graph.Id -and ($_.Scope -split " ") -contains "Calendars.ReadWrite" } |
Select-Object ClientId, ConsentType, PrincipalId