---
cve: "CVE-2026-48075"
severity: "MEDIUM"
cvss: 6.5
epss: "39%"
vendor: "open-reception"
kev: false
exploited: false
published: "2026-08-06 22:17:09"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-14T01:27:51+02:00"
---

# CVE-2026-48075

> 6.5 MEDIUM · 🧪 PoC

## Beschreibung

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-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- 4522a44c001782848faff5529d7c1e2be7ac9ef5 (Commit)

## Referenzen

- <https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-rhp5-vmcx-4qm8>
- <https://github.com/open-reception/appointment-booking-software/commit/4522a44c001782848faff5529d7c1e2be7ac9ef5>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48075) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_