Microsoft to Retire Microsoft 365 Companion Apps in December
Planned deprecation of Calendar, People, and Files apps affects managed Microsoft 365 environments
Key Takeaways
- Microsoft 365 Companion apps (Calendar, People, and Files) are scheduled for retirement on December 16, 2026.
- Administrators of managed devices are requested to remove the apps before the deprecation date.
- The retirement is a planned deprecation and not related to any security vulnerability or exploitation.
- No patches or security updates are involved; this is a routine lifecycle event.
- Organizations should review and remove the companion apps from managed devices to prevent functionality loss after December 16, 2026.
Quick answers
- What happened?
- Microsoft has announced the retirement of the Microsoft 365 Companion apps—Calendar, People, and Files—scheduled for December 16, 2026. Administrators of managed devices are being asked to remove these apps ahead of the deprecation date. The move is part of Microsoft's ongoing efforts to streamline its productivity suite and is not related to any security vulnerability or exploitation.
- Which products are affected?
- Microsoft 365
- What should defenders do?
- Administrators should remove the Microsoft 365 Companion apps (Calendar, People, and Files) from managed devices before December 16, 2026, to avoid loss of functionality.
Microsoft will retire the Calendar, People, and Files Microsoft 365 companion apps on December 16, 2026. In a notice to administrators, the company has requested that the apps be removed from managed devices prior to the retirement date. The companion apps, which integrate Calendar, People, and Files functionality into the Microsoft 365 ecosystem, will cease to function following the deprecation. This is a planned deprecation event and not a response to a security vulnerability or active exploitation. Organizations using these apps are advised to review their deployments and remove the companion apps from managed devices to avoid disruptions after the retirement date. No patches or security updates are associated with this change, as the retirement is a routine lifecycle decision by Microsoft.
Security Details
No security vulnerability or exploitation involved. This is a planned deprecation of Microsoft 365 Companion apps.
Affected products
Microsoft 365
Mitigation
Administrators should remove the Microsoft 365 Companion apps (Calendar, People, and Files) from managed devices before December 16, 2026, to avoid loss of functionality.
Sources
BleepingComputer
Microsoft to retire Microsoft 365 Companion apps in December
Sep 21, 2026 · 17:54
Original link
Related Security News
NeedyMantis Malware Used for Long-Term Persistence in Targeted Intrusions
Microsoft has identified a malware family named NeedyMantis being used by threat actors to maintain long-term, unauthorized access to already-breached networks. The malware has been observed in targeted intrusions across a range of sectors, including telecommunications, universities, medical nonprofits, intergovernmental organizations, and government contractors. Activity has been tracked since at least 2023 and remains ongoing.
_Dzmitry_Skazau_Alamy.jpg?width=720&quality=80&disable=upscale)
