Teamjs returning incorrect UPN for guest users in a AAD tenant

[ashishsaini11]

For guest users in a tenant, the UPN returned by Teams JS is not correct. It returns the guest user's email address instead of the actual UPN, which includes #EXT. This discrepancy causes issues with identifying users.
Actual UPN:

Returned by teamsjs

[lakhveerk]

Hi Ashish!
Thank you for reporting the issue. Can you answer some questions to help investigate the issue please:

1. What API you were using to get the UPN info?
2. I assume this happened in Teams host. What Teams version are you using?
3. Is this something new that you have started noticing or was that always returning email instead of UPN?

[priytosh-tripathi]

Hi lakhveerk,

Here is what we found,

1. We're using authenticaion.getuser.
2. We've got the result from Host Names - Teams and TeamsModern. Our customers are facing issues on both of these Hosts.
3. We've started noticing this issues 2 months back, but we're not sure when it all started. Upon investigation we found this issue.

[ChetanSharma-msft]

Hello @priytosh-tripathi - Could you please share the teamsJS and other Teams client related versions?

[ashishsaini11]

@ChetanSharma-msft we are using 2.22.0 of teams-js.

[Meghana-MSFT]

@ashishsaini11 - We are able to repro this. We raised a bug for this, we will keep you posted on the updates. Thank you.

[ashishsaini11]

Thanks @Meghana-MSFT . Could you please share the workitem which we can track.

[Meghana-MSFT]

@ashishsaini11 - Unfortunately the bug is internal to Microsoft, and we cannot share it outside.

[Meghana-MSFT]

@ashishsaini11 - This bug has been fixed, we have verified the fix at our end. Could you also please check once at your end.

[ashishsaini11]

We have tested the scenario and it is not working in all the scenarios. for some of the users it is still returning incorrect upn