CVE-2026-48075

Received Received - Intake

Unauthenticated Appointment Creation in OpenReception

Publication date: 2026-08-06

Last updated on: 2026-08-06

Assigner: GitHub, Inc.

Description

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.5, the `add-to-tunnel` endpoint creates a new appointment row in any client tunnel without any caller authentication. A request that supplies any valid `tunnelId` and any valid `emailHash` (the two need not belong to the same tunnel) results in an inserted appointment with `status = "CONFIRMED"`, attacker-controlled ciphertext fields, attacker-controlled date and duration, and an attacker-chosen agent. The endpoint validates only that some tunnel exists with the given `emailHash`, then writes the appointment using the attacker-supplied `tunnelId` directly. The `emailHash` lookup is effectively an existence check on the tenant; it does not authenticate the caller as the owner of the supplied `tunnelId`. Combined with the absence of any session, Authorization header, booking access token, or PoW, this makes the endpoint accept arbitrary appointment writes into arbitrary tunnels. By contrast, the sibling endpoint `create-new-client` (used to bootstrap a brand-new client tunnel) requires a Bearer bootstrap booking access token issued by the bootstrap-challenge / bootstrap-verify flow. The `add-to-tunnel` endpoint, intended for return-clients booking additional appointments, has no equivalent gate. The application's own middleware confirms this is intentional: `add-to-tunnel` is explicitly listed in the apiAuthHandle public-route allowlist alongside the bootstrap and challenge endpoints (which legitimately have no session). Version 1.0.5 fixes the issue.

CVSS Scores

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Meta Information

Published

2026-08-06

Last Modified

2026-08-06

Generated

2026-08-07

AI Q&A

2026-08-07

EPSS Evaluated

N/A

NVD

CVE-2026-48075

Affected Vendors & Products

Vendor	Product	Version / Range
openreception	appointment_booking_software	to 1.0.5 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-862	The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

Executive Summary

This vulnerability in OpenReception's appointment booking software allows attackers to create unauthorized appointments in any client tunnel without authentication. The flaw exists in the add-to-tunnel endpoint, which fails to verify if the caller owns the tunnel they are trying to access. Attackers can exploit this by providing a valid tunnel ID and email hash (even if unrelated) to insert fake appointments with attacker-controlled details like date, duration, and agent.

Detection Guidance

This vulnerability allows unauthorized appointment creation in any tunnel via the add-to-tunnel endpoint without authentication. To detect it, monitor for unexpected appointment entries with attacker-controlled fields (ciphertext, date, duration, agent) in the database or application logs. Check for POST requests to /add-to-tunnel with valid tunnelId and emailHash parameters but no session or authorization headers.

Impact Analysis

This vulnerability could allow unauthorized individuals to book fake appointments in your system, potentially disrupting schedules, overbooking resources, or impersonating legitimate users. Attackers could manipulate appointment details to cause confusion or misuse your booking platform.

Compliance Impact

This vulnerability could lead to unauthorized appointment creation in any client tunnel, potentially exposing sensitive appointment data. For GDPR, this may violate principles of data protection and user consent. For HIPAA, it risks unauthorized access to protected health information if appointment details are manipulated.

Mitigation Strategies

Upgrade OpenReception's appointment booking software to version 1.0.5 or later to address the authentication bypass in the add-to-tunnel endpoint.

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