CVE-2026-5818CWE-253

MCU Firmware Update Authentication Bypass on Caliptra Core

High · published June 23, 2026

CVSS v4.0
7.2
EPSS
0%
Percentile
14.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.2 · HIGH
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
EPSS
0.00245 · 14.9th percentile
Weakness
CWE-253 · Incorrect Check of Function Return Value
Published
2026-06-23T23:50Z
EPSS history
Timeline
  • 23 JUN 23:50Z
    MCU Firmware Update Authentication Bypass on Caliptra Core
    cvelistv5