# 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.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2026
- **Updated:** 7 Aug 2026
- **Also known as:** GHSA-rhp5-vmcx-4qm8

## 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 (Missing Authorization)

## 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.

## Is CVE-2026-48075 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48075 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48075 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48075 exists.

Affected product: open-reception appointment-booking-software. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48075/ (Markdown: https://insights.sbomify.com/CVE-2026-48075/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48075
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48075
- OSV: https://osv.dev/vulnerability/CVE-2026-48075

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-48075/
Summaries are generated and may contain mistakes; the official description above is the record.