Description
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.
Published: 2026-08-06
Score: 5.8 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The flaw allows a malicious actor to lock out a patient across all tenants that share the same email hash on an OpenReception instance. By repeatedly sending failed PIN challenge responses against one tenant, the attacker causes the shared throttle row to trigger a lockout that applies to the same email address on every tenant. Each failed attempt escalates the lockout duration, leading to sustained denial of service when the victim attempts to schedule appointments on any tenant.

Affected Systems

OpenReception appointment‑booking software, versions prior to 1.0.4, uses a central challenge_throttle table shared by all tenants. The fix was applied in version 1.0.4.

Risk and Exploitability

The CVSS score of 5.8 indicates a moderate severity that mainly affects availability. The EPSS score is not available, and the vulnerability is not listed in CISA KEV. Attackers only need to know the target’s email and have access to an API endpoint on at least one tenant. The attack path is remote and does not require privileged credentials.

Generated by OpenCVE AI on August 7, 2026 at 00:35 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the vendor-published update to version 1.0.4 or later.
  • If an immediate upgrade is not possible, modify the API layer to enforce tenant‑specific throttle keys so that each tenant’s challenge failures are counted separately.
  • Extend monitoring of the challenge_throttle activity or API metrics, and generate alerts for repeated failures targeting the same email address across tenant boundaries.

Generated by OpenCVE AI on August 7, 2026 at 00:35 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Sat, 08 Aug 2026 03:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 07 Aug 2026 10:30:00 +0000

Type Values Removed Values Added
First Time appeared Open-reception
Open-reception appointment-booking-software
Vendors & Products Open-reception
Open-reception appointment-booking-software

Thu, 06 Aug 2026 22:15:00 +0000

Type Values Removed Values Added
Description 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.
Title OpenReception's client PIN challenge throttle is keyed by emailHash only, allowing cross-tenant lockout
Weaknesses CWE-307
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}

Subscriptions

Open-reception Appointment-booking-software
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-08T02:26:36.396Z

Reserved: 2026-05-20T18:25:25.708Z

Link: CVE-2026-48071

cve-icon Vulnrichment

Updated: 2026-08-08T02:26:30.538Z

cve-icon NVD

Status : Received

Published: 2026-08-06T22:17:09.680

Modified: 2026-08-08T03:16:45.900

Link: CVE-2026-48071

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-07T09:59:10Z

Weaknesses
  • CWE-307

    Improper Restriction of Excessive Authentication Attempts