Plat'Home OpenBlocks IoT FX1 up to 5.0.8 authentication bypass

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.8$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in Plat'Home OpenBlocks IoT DX1, OpenBlocks IoT EX, BX models, OpenBlocks IX9 models with FW, OpenBlocks IoT VX2, OpenBlocks IDM RX1 and OpenBlocks IoT FX1 up to 5.0.8. This affects an unknown part. Executing a manipulation can lead to authentication bypass. This vulnerability is tracked as CVE-2026-21411. The attack is only possible within the local network. No exploit exists.

Detailsinfo

A vulnerability has been found in Plat'Home OpenBlocks IoT DX1, OpenBlocks IoT EX, BX models, OpenBlocks IX9 models with FW, OpenBlocks IoT VX2, OpenBlocks IDM RX1 and OpenBlocks IoT FX1 up to 5.0.8 and classified as critical. This vulnerability affects an unknown function. The manipulation with an unknown input leads to a authentication bypass vulnerability. The CWE definition for the vulnerability is CWE-288. A product requires authentication, but the product has an alternate path or channel that does not require authentication. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Authentication bypass issue exists in OpenBlocks series versions prior to FW5.0.8, which may allow an attacker to bypass administrator authentication and change the password.

The advisory is available at plathome.co.jp. This vulnerability was named CVE-2026-21411 since 01/05/2026. The exploitation appears to be easy. The attack needs to approached within the local network. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 01/06/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.8

VulDB Base Score: 8.8
VulDB Temp Score: 8.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.8
CNA Vector (jpcert): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authentication bypass
CWE: CWE-288 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/05/2026 CVE reserved
01/06/2026 +1 days Advisory disclosed
01/06/2026 +0 days VulDB entry created
01/06/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: plathome.co.jp
Status: Confirmed

CVE: CVE-2026-21411 (🔒)
GCVE (CVE): GCVE-0-2026-21411
GCVE (VulDB): GCVE-100-339682

Entryinfo

Created: 01/06/2026 08:18
Changes: 01/06/2026 08:18 (73)
Complete: 🔍
Cache ID: 216::103

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