Auth bypass in Beecue Fastbee
CVE-2026-121556
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.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/beecue/FastBee/issues/32 (issue-tracking)
- github.com/kerwincui/FastBee (product)
- github.com/beecue/FastBee/commit/3393e3223965a9dc9682dfb2bd37635fffa0fbd2 (patch)
- github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-open-api/src/main/j… (technical-description)
- github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot… (technical-description)
- github.com/kerwincui/FastBee/blob/v2.1.0/springboot/fastbee-service/fastbee-iot… (technical-description)
- www.vulncheck.com/advisories/fastbee-through-2.1.0-idor-via-iot-product-by-id-e… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121556?
- CVE-2026-121556 is a high-severity vulnerability in Beecue Fastbee, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.3/10. Published 2026-11-03.
- How severe is CVE-2026-121556?
- High severity. CVSS v3 base score is 8.3 out of 10.