CVE-2026-5818
MCU Firmware Update Authentication Bypass on Caliptra Core
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.
INFO
Published Date :
June 23, 2026, 11:50 p.m.
Last Modified :
June 23, 2026, 11:50 p.m.
Remotely Exploit :
No
Source :
Caliptra
Affected Products
The following products are affected by CVE-2026-5818
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | b01ddd03-5ef6-483b-b2c5-acba77f1a554 |
Solution
- Update Caliptra Core Runtime Firmware.
- Verify MCU FW integrity after update.
- Ensure proper function return value checks.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-5818 vulnerability anywhere in the article.