As per several reports from users across the world, Microsoft
Teams users have received a weird notification from the
company’s app. The alert is titled “Microsoft Teams FCM” and
content is simply “Test notification!”.
Microsoft sent out this suspicious-looking notification to
Teams users on Thursday morning, leading them to believe that
Microsoft Teams is broken or down. We understand that these
notifications could be linked to a bug in Google’s Firebase
platform and Microsoft is testing the service using these
The notification, as reported by several users on Twitter and
other social media platforms, just reads “FCM Messages” with
“test notification” right below it.
“Testing notification from Microsoft to investigate the
problem,” another notification reads.
“It was sent to a “fcm_fallback_notification_channel” and the
icon for the notification was not the normal teams icon but a
sold circle,” one user noted on Reddit.
Tapping on the notification doesn’t seem to do anything beyond
closing the alert popup, which appeared on mobile devices. For
now, these notifications appear to be harmless and you can
safely ignore them.
What is “FCM Messages” notification in Microsoft Teams?
FCM stands for Firebase Cloud Messaging (FCM), a Google-owned
service, which many of Google’s apps and Microsoft apps use to
deliver notifications on mobile devices.
Last week, a vulnerability was discovered in Firebase Cloud
Messaging (FCM), which allowed attackers to exploit FCM keys
stored in APK files.
It appears that Microsoft sent users a notification while
trying to test the FCM service after Google patched the
vulnerability. The mass “Microsoft Teams FCM Messages” messages
are likely tied to recent events around Google’s Firebase Cloud
Following that, Microsoft released an official statement
through Office 365 dashboard, which states, “Some users may
receive unexpected Test notifications on their mobile devices”.
“We’re investigating an issue where users may receive text
notifications on their mobile devices,” Microsoft said.
Update 1: Microsoft’s investigation has determined that
this issue affects Android users specifically, and they’re
working on a fix. For now, users are recommended to dismiss
these notifications without interacting with them.