---
cve: "CVE-2026-48086"
severity: "CRITICAL"
cvss: 9.9
epss: "33%"
vendor: "open-reception"
kev: false
exploited: false
published: "2026-08-06 22:17:11"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-15T17:53:17+02:00"
---

# CVE-2026-48086

> 9.9 CRITICAL · 🧪 PoC

## Beschreibung

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, a TENANT_ADMIN promotes themselves to platform-wide GLOBAL_ADMIN through a single PUT request. The role-update handler accepts the `GLOBAL_ADMIN` enum value from any tenant admin updating their own tenant's staff. No policy check enforces that "only an existing GLOBAL_ADMIN may grant GLOBAL_ADMIN", so the schema validation IS the authorization decision. After re-login, the JWT contains the new role and the formerly-tenant-scoped admin reaches every other tenant on the platform. On the hosted OpenReception service this is a scope-changed escalation: a single customer-side tenant administrator gains full platform-wide administrative control over all other tenants' configuration, users, staff records, operational metadata, and tenant lifecycle. Plaintext appointment contents remain subject to the E2E model unless chained with the staff-crypto poisoning issue (V-4) or with staff-passkey hijacking (V-1). On a single-tenant self-hosted deployment it is still a privilege escalation because TENANT_ADMIN should not be able to create new tenants, modify global configuration, or manage other administrators. The same handler also accepts updates targeted at any colleague within the tenant. A tenant admin can promote a separate collaborator account instead of themselves, leaving their own audit trail clean while the platform-wide breach happens through a separate identity. Version 1.0.2 fixes the issue.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 8525d35a41c31078d9f01c62e9687e653cf1a494 (Commit)

## Referenzen

- <https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-5qfr-7q4g-3469>
- <https://github.com/open-reception/appointment-booking-software/commit/8525d35a41c31078d9f01c62e9687e653cf1a494>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48086) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_