CVE-2026-48071 MEDIUM

CVE-2026-48071: OpenReception's client PIN challenge throttle is keyed by emailHash only, allowing cross-tenant lockout

Vendor Open-Reception
Product appointment-booking-software
Weakness CWE-307 · Brute force
Published August 6, 2026
Last update August 6, 2026

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

What the vulnerability does

01Description

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.4, the PIN-type challenge throttle uses `emailHash` as the only key. The throttle rows live in the central `challenge_throttle` table, which is shared across all tenants. Every tenant's `/api/tenants/{id}/appointments/verify-challenge` endpoint increments the same row when a PIN response fails, and every tenant's `/api/tenants/{id}/appointments/challenge` endpoint reads the same row when deciding whether to issue a new challenge. When the same `emailHash` exists in multiple tenants on the same OpenReception instance (the same patient holding tunnels in two different clinics that share the platform), an attacker who knows the patient's email can lock out that patient on tenant B by issuing failed challenge responses against tenant A. The attacker needs no relationship to tenant B; the lockout propagates through the shared throttle row. The lockout escalates with repeated failures. The first lockout triggers at 4 failed attempts and lasts approximately 60 seconds. Subsequent failures escalate the lockout duration to 5 minutes, 30 minutes, and 60 minutes per the throttle service's escalation logic. Repeated bursts produce sustained denial of service against the targeted email. Version 1.0.4 patches the issue.

Key dates

02Disclosure timeline

August 6, 2026 CVE published