CVE-2026-48494 in Typebot
Summary
by MITRE • 08/11/2026
TypeBot is a chatbot builder tool. In version 3.16.1, an authenticated user who has read access to any typebot can resume a WhatsApp preview webhook session that belongs to a different typebot by mixing an authorized `typebotId` and `blockId` and a foreign preview phone number tied to another preview session. The WhatsApp test-webhook handler authorizes the parent typebot first, but then resolves the preview chat session only by `wa-preview-{phone}`. As a result, an attacker can inject arbitrary webhook JSON into another workspace's WhatsApp preview session and advance its draft/unpublished flow without any access to the victim typebot. Version 3.17.0 patches the issue.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability in TypeBot version 3.16.1 represents a critical authorization bypass flaw that undermines the security boundaries between different user workspaces within the chatbot platform. This issue stems from an improper session management implementation in the WhatsApp preview webhook handler where the system validates access to the parent typebot but fails to properly authenticate the specific preview session being accessed. The flaw occurs when an authenticated user with read permissions on one typebot attempts to manipulate a WhatsApp preview session that belongs to another typebot by combining legitimate authorization parameters with unauthorized session identifiers.
The technical implementation of this vulnerability exploits a mismatch in the authentication flow where the system first verifies that the requesting user has access to the specified `typebotId` and `blockId` but subsequently resolves the preview chat session using only the `wa-preview-{phone}` identifier without proper validation of the session ownership. This creates a path where an attacker can inject arbitrary webhook JSON payloads into another workspace's preview session, effectively allowing them to manipulate draft flows and advance conversations in unauthorized workspaces. The vulnerability specifically targets the WhatsApp test-webhook handler component which should enforce strict session isolation between different typebot instances.
The operational impact of this vulnerability extends beyond simple data exposure to include potential workflow manipulation and unauthorized content injection across different user workspaces. An attacker could leverage this flaw to insert malicious payloads, modify conversation flows, or potentially execute unintended actions within the victim's preview environment without having any direct access to the target typebot's configuration or content. This represents a significant bypass of the platform's access control mechanisms that should prevent cross-workspace data manipulation and flow interference.
This vulnerability aligns with CWE-285: Improper Authorization, specifically manifesting as an authorization bypass where the system fails to properly validate session ownership during preview webhook processing. The issue also relates to ATT&CK technique T1078: Valid Accounts which demonstrates how authenticated users can exploit legitimate access privileges to gain unauthorized access to other resources within the same platform. Additionally, the flaw demonstrates characteristics of privilege escalation through improper session handling as outlined in CWE-269: Improper Privilege Management.
The security implications of this vulnerability are particularly concerning given that it allows manipulation of draft/unpublished flows which could potentially be used for social engineering attacks, malicious content injection, or disruption of legitimate workflow processes. The patch implemented in version 3.17.0 likely addresses the core session validation issue by ensuring that preview sessions are properly authenticated against their owning typebot and that the phone number associations are validated within the correct workspace context.
Organizations using TypeBot should implement immediate mitigations including verifying that all preview sessions are properly isolated between different workspaces, enforcing stricter session validation during webhook processing, and ensuring that any cross-typebot operations require explicit authorization. The fix should include proper session ownership verification before allowing any manipulation of preview flows, preventing the injection of arbitrary JSON payloads into unauthorized preview environments while maintaining legitimate functionality for authorized users.