CVE-2026-5818

MCU Firmware Update Authentication Bypass on Caliptra Core

Published Jun 23, 2026 CVSS 4.0 · 7.2 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Caliptra
Caliptra core Runtime Firmware
Vendors & Products Caliptra
Caliptra core Runtime Firmware
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title MCU Firmware Update Authentication Bypass on Caliptra Core
Weaknesses CWE-253
References
Metrics cvssV4_0

{'score': 7.2, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Caliptra
Published
Updated
Jun 24, 2026, 1:04 PM
Reserved
Apr 8, 2026, 3:45 PM
Status
Awaiting Analysis
Published
Jun 24, 2026, 12:16 AM
Modified
Oct 25, 2026, 11:10 PM