Wekan: OIDC Account Takeover via Unconditional Email-Based Account Merge in onCreateUser hook

Wekan is open source kanban built with Meteor. Prior to 9.32, the Wekan Accounts.onCreateUser hook in server/models/users.js merges OIDC logins into existing accounts when the OIDC email or username matches an existing Wekan user, without verifying ownership or checking email_verified. An attacker using an OIDC provider account with a victim's email or username can cause Wekan to merge the attacker's OIDC credentials into the victim account and then log in as that account. This issue is fixed in version 9.32.