CVE-2026-48076
OpenReception's bootstrap booking flow allows unauthenticated booking on isPublic=false channels
Description
OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. The new-client booking flow in versions 1.0.1 and prior consists of three calls: `bootstrap-challenge` (returns a 16-bit PoW challenge with `difficulty=4` leading hex zeroes), `bootstrap-verify` (validates the PoW and issues a Bearer booking access token), and `create-new-client` (consumes the token and creates the tunnel and first appointment). The token correctly binds to `tenantId`, `tunnelId`, `clientPublicKey`, and `emailHash`, but never to `channelId`. The `bootstrap-challenge` request schema does not even accept a `channelId`, and the issued token's payload contains no channel information. Independently, the service function `createNewClientWithAppointment` checks only `channel.archived = false`. The `channel.isPublic` check that protects `addAppointmentToTunnel` is missing in the new-client path. The combination means: an attacker completes the bootstrap flow normally (16-bit PoW, completes in well under one second on commodity hardware, no rate limiting beyond the throttle store), receives a valid booking access token, and then submits the `create-new-client` payload with `channelId` pointing to a private (`isPublic = false`) channel. The booking lands as `CONFIRMED` if the target channel has `requiresConfirmation = false` (the default), otherwise as `NEW`. The patient-facing UI does not list private channels in its picker (`/api/public/channels` correctly filters `isPublic = true`), so the channel ID must be obtained out of band. The companion finding V-10 (schedule endpoint discloses private channels) provides exactly that: a single unauthenticated GET reveals every private channel ID for any tenant. V-10 plus V-11 together make private channels fully reachable to anonymous attackers. As of time of publication, no known patched versions are available.
INFO
Published Date :
Aug. 6, 2026, 10:17 p.m.
Last Modified :
Aug. 6, 2026, 10:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-48076
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Validate channelId in bootstrap-verify
- Validate channelId in create-new-client
- Add channelId to bootstrap-challenge
- Implement rate limiting for bootstrap flow
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-48076.
| URL | Resource |
|---|---|
| https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-3658-3j75-p5j3 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48076 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-48076
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48076 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48076 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 06, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'open-reception', 'product': 'appointment-booking-software', 'versions': [{'status': 'affected', 'version': '<= 1.0.1'}]}] Added Description OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. The new-client booking flow in versions 1.0.1 and prior consists of three calls: `bootstrap-challenge` (returns a 16-bit PoW challenge with `difficulty=4` leading hex zeroes), `bootstrap-verify` (validates the PoW and issues a Bearer booking access token), and `create-new-client` (consumes the token and creates the tunnel and first appointment). The token correctly binds to `tenantId`, `tunnelId`, `clientPublicKey`, and `emailHash`, but never to `channelId`. The `bootstrap-challenge` request schema does not even accept a `channelId`, and the issued token's payload contains no channel information. Independently, the service function `createNewClientWithAppointment` checks only `channel.archived = false`. The `channel.isPublic` check that protects `addAppointmentToTunnel` is missing in the new-client path. The combination means: an attacker completes the bootstrap flow normally (16-bit PoW, completes in well under one second on commodity hardware, no rate limiting beyond the throttle store), receives a valid booking access token, and then submits the `create-new-client` payload with `channelId` pointing to a private (`isPublic = false`) channel. The booking lands as `CONFIRMED` if the target channel has `requiresConfirmation = false` (the default), otherwise as `NEW`. The patient-facing UI does not list private channels in its picker (`/api/public/channels` correctly filters `isPublic = true`), so the channel ID must be obtained out of band. The companion finding V-10 (schedule endpoint discloses private channels) provides exactly that: a single unauthenticated GET reveals every private channel ID for any tenant. V-10 plus V-11 together make private channels fully reachable to anonymous attackers. As of time of publication, no known patched versions are available. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Added CWE CWE-863 Added Reference https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-3658-3j75-p5j3