# CVE-2026-121556: FastBee through 2.1.0 IDOR via /iot/product By-ID Endpoints

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/beecue/FastBee/commit/3393e3223965a9dc9682dfb2bd37635fffa0fbd2

## Affected products and versions

- beecue / FastBee: ≥ 0; ≤ 2.1.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 8.3 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L; source: CNA: VulnCheck

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 8.3 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-639

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/beecue/FastBee/issues/32 (CNA: VulnCheck; issue-tracking)

- https://github.com/kerwincui/FastBee (CNA: VulnCheck; product)

- https://github.com/beecue/FastBee/commit/3393e3223965a9dc9682dfb2bd37635fffa0fbd2 (CNA: VulnCheck; patch)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-open-api/src/main/java/com/fastbee/data/controller/ProductController.java#L77-L141 (CNA: VulnCheck; technical-description)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot-service/src/main/java/com/fastbee/iot/service/impl/ProductServiceImpl.java#L72-L92 (CNA: VulnCheck; technical-description)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot-service/src/main/resources/mapper/iot/ProductMapper.xml#L37-L67 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/fastbee-through-2.1.0-idor-via-iot-product-by-id-endpoints (CNA: VulnCheck; third-party-advisory)

- https://github.com/beecue/FastBee/commit/3393e3223965a9dc9682dfb2bd37635fffa0fbd2 (disclosure@vulncheck.com)

- https://github.com/beecue/FastBee/issues/32 (disclosure@vulncheck.com)

- https://github.com/kerwincui/FastBee (disclosure@vulncheck.com)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-open-api/src/main/java/com/fastbee/data/controller/ProductController.java#L77-L141 (disclosure@vulncheck.com)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot-service/src/main/java/com/fastbee/iot/service/impl/ProductServiceImpl.java#L72-L92 (disclosure@vulncheck.com)

- https://github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot-service/src/main/resources/mapper/iot/ProductMapper.xml#L37-L67 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/fastbee-through-2.1.0-idor-via-iot-product-by-id-endpoints (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-121556; retrieved 2026-11-03; source updated 2026-11-03

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121556; retrieved 2026-11-03; source updated 2026-11-03

Revision: f5d3b44d20bcb90ed5297c8774d188b73ac1cc7d25ac0cffd24aa0549820d83d

Canonical: https://y2.dev/cve/CVE-2026-121556

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