Unplanned Outage: Microsoft 365 Services Temporarily Unavailable via Legacy ADFS
Last Updated:
2026-08-08 09:27:31
Event:
2026-08-07 17:47:00
Status:
Closed
Brief Description:
Resolved: The legacy Active Directory Federation Services (ADFS) is temporarily unavailable. Most Cornell community members will not be affected as only a small number of accounts are on the legacy ADFS.
User Impact:
Anyone accessing Microsoft 365 (Outlook, Teams, Office, etc.) via the legacy ADFS will potentially experience an interruption in service. Most Cornell community members will not be affected as only a small number of accounts are on the legacy ADFS.
Workaround:
There is no workaround for this issue
Current Status:
The issue is resolved.
Services Affected:
Authentication and Authorization
Collaboration Platforms
Email and Calendar
Subsites Affected:
Microsoft Teams
Office 365 Productivity Bundle
Outlook for Mac
Outlook for Windows
Outlook on the Web
Full Description:
The legacy Active Directory Federation Services (ADFS) is temporarily unavailable. Most Cornell community members will not be affected as only a small number of accounts are on the legacy ADFS.
CIT TDX ID:
2358504
Timeline of Changes
| Description | Current Status | Date | Time |
|---|---|---|---|
The legacy Active Directory Federation Services (ADFS) is temporarily unavailable. Most Cornell community members will not be affected as only a small number of accounts are on the legacy ADFS. |
The issue is resolved. |
2026-08-08 | 09:27:31 |
| The legacy Active Directory Federation Services (ADFS) is temporarily unavailable. Most Cornell community members will not be affected as only a small number of accounts are on the legacy ADFS. | The IT Security Office is investigating the issue and will provide periodic updates. |
2026-08-07 | 18:12:40 |