UEFI BIOS Shell Secure Boot Bypass

Executive Summary

CVE-2026-6485 is a vulnerability in InsydeH2O UEFI BIOS versions up to 8.2 that allows bypassing Secure Boot protections. It can be exploited through the UEFI BIOS embedded Shell using shell commands or startup scripts.

Useful 0 Not Useful 0

Detection Guidance

Check if your system uses InsydeH2O UEFI BIOS versions up to 8.2 by inspecting BIOS version via system information tools or commands like 'wmic bios get smbiosbiosversion' on Windows or 'dmidecode -t bios' on Linux. Look for active debug code or unexpected shell access in BIOS settings or logs.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability could allow attackers with local access to bypass Secure Boot, potentially leading to unauthorized system access, malware execution, or data theft. It impacts confidentiality, integrity, and availability of the system.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability allows bypassing Secure Boot via UEFI BIOS embedded Shell, potentially enabling unauthorized access to system firmware and boot processes. Such bypasses could undermine security controls required by GDPR (data protection) and HIPAA (health data safeguards) by allowing attackers to install persistent malware or exfiltrate sensitive data before the OS loads.

Useful 0 Not Useful 0

Mitigation Strategies

Update InsydeH2O UEFI BIOS to the latest kernel versions (5.2B.17, 5.3A.17, 5.48.17, 5.56.17, 5.63.17, or 5.72.17) provided by Insyde. Disable the UEFI BIOS embedded Shell if not required and review startup scripts for unauthorized commands.

Useful 0 Not Useful 0