---
id: "CVE-2026-121556"
kind: "vulnerability"
aliases: ["CVE-2026-121556"]
title: "FastBee: IDOR in ProductController lets tenants read and edit other tenants' products"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["fastbee", "iot", "mqtt", "multi-tenant", "other"]
not_affected_if: ["no-untrusted-accounts", "single-tenant"]
published_at: "2026-11-03T16:17:27+00:00"
first_seen_at: "2026-11-03T16:21:44+00:00"
updated_at: "2026-11-03T16:23:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121556", "first_seen_at": "2026-11-03T16:21:44+00:00"}]
---

# FastBee: IDOR in ProductController lets tenants read and edit other tenants' products

FastBee, an IoT platform, has an insecure direct object reference in its ProductController, so an authenticated user can access products belonging to other tenants by supplying their product IDs. An attacker can enumerate sequential IDs to read MQTT account credentials and secrets, change product configuration, or delete products.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed FastBee version; the sources say the flaw affects versions through `2.1.0`.
- Review whether tenant users can call the product endpoints with IDs outside their own tenant.

## Fix

- Patch referenced in the sources (github.com); the fixed version is not stated in the sources.

## Timeline

- 2026-11-03T16:21:44+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121556

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/fastbee-through-2.1.0-idor-via-iot-product-by-id-endpoints
- [fix] Patch: github.com https://github.com/beecue/FastBee/commit/3393e3223965a9dc9682dfb2bd37635fffa0fbd2

## From the sources

FastBee through 2.1.0 contains an insecure direct object reference vulnerability in ProductController that allows authenticated tenant users to access other tenants' products by supplying their product IDs. Attackers can enumerate sequential product IDs to read MQTT account, password, and secret values, overwrite product configuration including tenant_id, or delete products with cascading rows.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_