CVE-2026-5818: MCU Firmware Update Authentication Bypass on Caliptra Core
Incorrect check of function return value in Caliptra Core Runtime Firmware (ActivateFirmwareCmd::activatefw modules) allows bypass of Caliptra Core's verification of the MCU FW during a hitless update.
This issue affects Core Runtime Firmware: from 2.0.0 through 2.0.1, 2.1.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Caliptra Core Runtime Firmware (ActivateFirmwareCmd::activate_fw modules)to a version that resolves this vulnerability.Fixed in 2.0.1 - Upgrade
Upgrade
Caliptra Core Runtime Firmware (ActivateFirmwareCmd::activate_fw modules)to a version that resolves this vulnerability.Fixed in 2.1.0
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5818?
CVE-2026-5818 has a severity rating of 7.2, which is classified as high.
How do I fix CVE-2026-5818?
To fix CVE-2026-5818, update the Caliptra Core Runtime Firmware to version 2.0.2 or later.
What is the risk associated with CVE-2026-5818?
CVE-2026-5818 has a risk score of 63, indicating a significant vulnerability that requires immediate attention.
What components are affected by CVE-2026-5818?
CVE-2026-5818 affects the Caliptra Core Runtime Firmware versions from 2.0.0 through 2.1.0.
What is the nature of the vulnerability in CVE-2026-5818?
CVE-2026-5818 is an authentication bypass vulnerability that allows unauthorized firmware updates to the MCU.