CVE-2026-5818: Caliptra Core Runtime Firmware

High severity, CVSS 7.2. EPSS: 0.2% chance of exploitation in the next 30 days.

Incorrect check of function return value in Caliptra Core Runtime Firmware (ActivateFirmwareCmd::activate_fw 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 products

• Caliptra Core Runtime Firmware: from 2.0.0, up to and including 2.0.1; version 2.1.0 only

Published 2026-06-24. Last modified 2026-06-25.