QueryWeaver Authentication Bypass via Email Signup Token Issuance for Existing Accounts

QueryWeaver contains an authentication bypass vulnerability that allows unauthenticated attackers to obtain valid session tokens for existing accounts by submitting a signup request with a known victim email address. The signup route unconditionally creates and links a new token to the matching Identity via a Cypher MERGE operation before checking whether the email belongs to an existing account, causing the server to return a valid authenticated session token for the victim's identity without requiring any prior credentials or user interaction.