MCU Firmware Update Authentication Bypass on Caliptra Core_CVE-2026-5818

7.2 / 10

HIGH

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

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.

Basic Information

ID CVE-2026-5818

Source Caliptra

Published Jun 23, 2026 at 23:50

Affected Product

Vendor Caliptra

Product Core Runtime Firmware

Version 2.0.0

Affected Versions Caliptra Core Runtime Firmware 2.0.0
Caliptra Core Runtime Firmware 2.1.0

CWE Classification

CWE-253

References

github.com /chipsalliance/caliptra-sw/security/advisories/GHSA-456r-gcjr-6rxq

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    "published": "2026-06-23T23:50:06.556Z",
    "modified": "2026-06-23T23:50:06.556Z",
    "type": "cve",
    "title": "MCU Firmware Update Authentication Bypass on Caliptra Core",
    "source": "Caliptra",
    "references": "https://github.com/chipsalliance/caliptra-sw/security/advisories/GHSA-456r-gcjr-6rxq",
    "id": "CVE-2026-5818",
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    "sourceData": "Caliptra Core Runtime Firmware 2.0.0\nCaliptra Core Runtime Firmware 2.1.0",
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