Which versions of ShizenBox2 are affected by CVE-2026-80253?

ShizenBox2 devices running dev-conf firmware version 1.0.10 and earlier allow unauthenticated bootloader command execution to any person with physical device access, enabling complete firmware…

How to fix or mitigate CVE-2026-80253?

Within 24 hours, inventory all ShizenBox2 instances and identify which are running dev-conf firmware ≤v1.0.10. Within 7 days, implement physical access controls such as locked enclosures or restricted-area placement for all vulnerable devices, and document current firmware versions and bootloader access logs. Within 30 days, transition production systems away from dev-conf to production firmware where feasible, or await and deploy any firmware updates released by Shizen Connect Inc. beyond v1.0.10.

ShizenBox2 CVE-2026-80253

Q: What is the CVSS score of CVE-2026-80253?

CVE-2026-80253 has a CVSS 4.0 base score of 7.0 (High). CVSS vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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. EPSS exploitation probability: 0.3%.

EUVD-2026-70367 HIGH

Improper Physical Access Control (CWE-1263)

2026-09-03 jpcert

GHSA-9whx-x3gf-f75p

Shizenbox2 Dev Conf

7.0

CVSS 4.0 · Vendor: jpcert

Severity by source

Vendor (jpcert) PRIMARY

7.0 MEDIUM

CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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

vuln.today AI

6.8 MEDIUM

Physical access required (AV:P), no authentication on bootloader interface (PR:N), full CIA impact on the device attainable once physical access is obtained.

3.1 AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

4.0 AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (jpcert).

CVSS VectorVendor: jpcert

Attack Vector

Physical

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Sep 03, 2026 - 13:16 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Sep 03, 2026 - 13:07 vuln.today

cvss_changed

Severity Changed

Sep 03, 2026 - 13:07 NVD

MEDIUM HIGH

CVSS changed

Sep 03, 2026 - 13:07 NVD

6.8 (MEDIUM) 7.0 (HIGH)

Metadata Corrected

Sep 03, 2026 - 09:40 vuln.today

tag: Information Disclosure removed

Analysis Generated

Sep 03, 2026 - 09:22 vuln.today

DescriptionCVE.org

An improper physical access control issue exists in ShizenBox2 (dev-conf). If exploited, an attacker with physical access to the product may execute bootloader commands without authentication.

AnalysisAI

Unauthenticated bootloader command execution in ShizenBox2 (dev-conf) firmware ≤v1.0.10 is achievable by any attacker with physical access to the device. The 'dev-conf' firmware variant from Shizen Connect Inc. …

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Vulnerability AssessmentAI

Exploitation	Physical access to the ShizenBox2 hardware is the sole prerequisite - no network path, no credentials, and no special software are required. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The CVSS 4.0 vector (AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H) precisely scopes the risk: exploitation requires physical proximity to the device, which fundamentally caps the threat to insider threats, device theft, supply-chain interdiction, or physical break-in scenarios. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation	No vendor-released patch version is independently confirmed from the available input data; consult the vendor advisory PDF at https://www.se-digital.net/wp-content/uploads/2026/08/CVE-2026-80253.pdf and the JVN entry at https://jvn.jp/en/jp/JVN91715694/ for firmware update guidance. … Detailed patch versions, workarounds, and compensating controls in full report.