Executive brief
TypeBot is a chatbot builder that allows businesses to automate customer interactions. A security flaw in its WhatsApp integration allows unauthorized individuals to send fake messages to the system by bypassing security checks. This could lead to the unauthorized use of paid AI resources, the corruption of customer data, and the triggering of automated business workflows without permission.
Technical details
The WhatsApp Cloud API webhook endpoint (POST /v1/workspaces/{workspaceId}/whatsapp/{credentialsId}/webhook) in TypeBot versions 3.16.1 and prior fails to validate the 'x-hub-signature-256' HMAC signature provided by Meta. Because the endpoint is defined as a public procedure without authentication, an attacker who knows or discovers the workspaceId and credentialsId (which are often exposed in web server logs or Meta's dashboard) can send crafted JSON payloads. This allows for the injection of spoofed messages into bot flows, potentially leading to unauthorized consumption of integrated services (like OpenAI) and pollution of the results database. The vulnerability was addressed in version 3.17.0 by implementing proper signature verification.
Affected products
- baptisteArno typebot.io <= 3.16.1
Timeline
- 2026-05-21: patched: Version 3.17.0 released
- 2026-05-22: disclosed: Security advisory published