--- cve: "CVE-2026-48088" severity: "CRITICAL" cvss: 9.4 epss: "29%" vendor: "open-reception" kev: false exploited: false published: "2026-08-06 22:17:11" tags: [cve, security, critical] source: tsecurity.de CVE-Dossier exported: "2026-09-16T09:48:39+02:00" --- # CVE-2026-48088 > 9.4 CRITICAL · 🧪 PoC ## Beschreibung OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.4, the route `POST /api/tenants/{tenantId}/staff/{staffId}/crypto` accepts and stores attacker-controlled ML-KEM-768 public keys against any tenant on the platform without authentication. The handler logs an "Unauthorized crypto key storage attempt" warning when neither a session nor a registration cookie is present, then proceeds to insert the row regardless. The platform's E2E claim that "even administrators cannot view sensitive information" is broken: any unauthenticated network attacker can register themselves as an additional encryption recipient for any tenant's future patient appointments. A second variant of the bug suppresses the unauthorized-warning log entry. The Zod schema makes the `email` field optional. When the request body omits `email` and the request carries no registration cookie, the comparison `registrationEmail === email` becomes `undefined === undefined`, which evaluates to `true`. The handler treats the request as a legitimate registration flow, skips the warning entirely, and stores the row. Successful storage is still recorded as an `[info]` log line, but the security-relevant warning that operators are most likely to monitor or alert on is gone. The `staff_crypto` table has no unique constraint on `user_id`, so an arbitrary number of attacker rows can coexist for the same staff identifier and all return as `is_active=true`. The supplied `staffId` does not need to match any existing user or pending invite. Schema validation on `passkeyId`, `publicKey`, and `privateKeyShare` is also weak: the literal string `` was accepted, indicating no length, format, or cryptographic-validity check beyond field presence. This weakness is independent of the auth bypass but compounds it: a poisoned directory can also be filled with malformed entries that break legitimate booking flows. The injected key is consumed by the public booking flow. After completing the unauthenticated `bootstrap-challenge` and `bootstrap-verify` ceremony as a "patient", the resulting `bookingAccessToken` is accepted by `GET /api/tenants/{id}/appointments/staff-public-keys`, which returns the attacker-controlled keys alongside any legitimate ones. A new appointment encrypts its tunnel key with ML-KEM to all listed recipients, so the attacker becomes a co-recipient of the encryption and can decapsulate the tunnel key with the matching secret. From there, all appointment payloads for that booking are decryptable. Version 1.0.4 patches the issue. ## CVSS-Vektor ``` CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L ``` | Metrik | Wert | Bewertung | |---|---|---| | AV Angriffsvektor | Netzwerk | bad | | AC Komplexität | Gering | bad | | PR Privilegien | Keine | bad | | UI Interaktion | Keine | bad | | S Scope | Unverändert | good | | C Vertraulichkeit | Hoch | bad | | I Integrität | Hoch | bad | | A Verfügbarkeit | Gering | warn | ## Patch verfügbar (OSV) - 78dfd9317a0be0897e6e4d73afe670c07a75460f (Commit) ## Referenzen - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48088) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_