CVE-2026-48075 OpenReception's unauthenticated add-to-tunnel endpoint accepts arbitrary appointment injections
Unauthenticated attackers can inject arbitrary confirmed appointments into any client tunnel by exploiting a missing authorization check on the add-to-tunnel endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-48075?
CVE-2026-48075 is a medium-severity missing authorization vulnerability in open-reception appointment-booking-software, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-862
Which versions are affected by CVE-2026-48075?
How do I fix CVE-2026-48075?
No fix has been published for CVE-2026-48075 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-48075 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48075 exists.
Sources
Also known as GHSA-rhp5-vmcx-4qm8.