Nanobot prior to version 0.2.1 contains a server-side request forgery vulnerability in the Microsoft Teams channel handler that allows remote attackers to exfiltrate Bot Framework bearer tokens by supplying a forged activity with an attacker-controlled serviceUrl value. Attackers can poison the stored conversation reference by sending a crafted inbound activity to the Teams webhook, causing subsequent bot replies to transmit token-bearing Authorization header requests to an attacker-controlled host.