Is CVE-2026-5818 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-5818 being exploited in the wild.

How severe is CVE-2026-5818?

Informational severity, with a CVSS score of 7.2, published 24 June 2026.

Which products and versions are affected?

CHIPS Alliance Core Runtime Firmware 2.0.0, 2.0.1, 2.1.0.

Is there a fix for CVE-2026-5818?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-5818 attacked?

It is attacked from the adjacent network, in device firmware.

Am I affected by CVE-2026-5818?

Check whether you run CHIPS Alliance Core Runtime Firmware at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-5818: Caliptra Core Runtime Firmware authentication bypass in activate_fw

CVE-2026-5818 · Severity: info · CVSS 7.2 · Published 2026-06-24

Caliptra Core Runtime Firmware, which provides security services for hardware root-of-trust, contains a flaw in how it verifies firmware updates. An attacker with high privileges could bypass security checks to load unauthorized or malicious firmware onto the system during an update process. This could lead to a complete compromise of the hardware's security and the data it protects.

Technologies: CHIPS Alliance Core Runtime Firmware. Vendors: CHIPS Alliance.

Quick answers

Is CVE-2026-5818 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-5818 being exploited in the wild.
How severe is CVE-2026-5818?: Informational severity, with a CVSS score of 7.2, published 24 June 2026.
Which products and versions are affected?: CHIPS Alliance Core Runtime Firmware 2.0.0, 2.0.1, 2.1.0.
Is there a fix for CVE-2026-5818?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-5818 attacked?: It is attacked from the adjacent network, in device firmware.
Am I affected by CVE-2026-5818?: Check whether you run CHIPS Alliance Core Runtime Firmware at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability exists in the Caliptra Core Runtime Firmware within the `ActivateFirmwareCmd::activate_fw` module (specifically `runtime/src/activate_firmware.rs`). The root cause is an incorrect check of a function return value, which causes the firmware authorization check to be silently discarded during an MCU hitless update. This creates a Time-of-Check Time-of-Use (TOCTOU) risk where unauthorized MCU firmware can be loaded and executed without detection. Exploitation requires high privileges and an adjacent network position. The issue is addressed in patched versions 2.0.2 and 2.1.1.

Affected products

Caliptra Core Runtime Firmware 2.0.0, 2.0.1, 2.1.0

Timeline

2026-06-23: advisory: GitHub Security Advisory published
2026-06-24: disclosed: NVD publication date

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.