As a catastrophic security flaw, CVE-2026-48088 has severe implications, demanding immediate intervention.
Status: Deferred
Last updated: 🕣 08 Sep 2026, 20:51 UTC
Originally published on: 🕙 06 Aug 2026, 22:17 UTC
Time between publication and last update: 32 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
CVE-2026-48088: 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 `<placeholder-base64>` 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.
The exploitability of CVE-2026-48088 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
With low attack complexity and no required privileges, CVE-2026-48088 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-48088, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-48088, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.