I have removed a user but they have been added back in without my permission.

[Emily Fuller]

Hi everyone, 

I have removed a number of users as they have left the company. I revoked their access and then removed them from the administration. 

Over the last few days i have noticed that I get alerts that 'my team is growing' and the removed users have been given access again. 

I have since removed them again but does anyone know why this is happening? I wondered if it was people assigning them work by mistake would add them back in but I have tried to assign something to a removed user and they do not return as an assignee option. 

Any help would be appreciated as we are concerned for the security. 

[Prakash Kumar]

@Emily Fuller 

Two cases maybe 

1. The auto-create user using SSO if any cloud application integrated with the server. The deactivated user tries to log in to Jira using SSO. 
2. User provisioning app integrated with the server. 

Kind regards,

Prakash

[Krister Broman _Advania_]

Do you have any kind of Active Directory sync running? 

Have you looked in the log to see what has happened with the specific users?