Is CVE-2026-33243 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-33243 being exploited in the wild.

How severe is CVE-2026-33243?

High severity, with a CVSS score of 8.2, published 20 March 2026.

Which products and versions are affected?

Barebox 2016.03.0 to before 2026.03.1 (also affects 2025.09.x before 2025.09.3).

Is there a fix for CVE-2026-33243?

A patch was published on 2026-03-17: Patch included in barebox v2026.03.1 and v2025.09.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-33243 attacked?

It is attacked with local access or with physical access, in device firmware.

Am I affected by CVE-2026-33243?

Check whether you run Barebox 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-2026-33243: barebox FIT signature verification bypass

CVE-2026-33243 · Severity: high · CVSS 8.2 · Published 2026-03-20

barebox is a bootloader used in embedded systems to load and verify the operating system kernel. A vulnerability in its FIT (Flat Image Tree) signature verification allows an attacker with physical or local storage access to modify boot images without detection, potentially compromising all privilege levels including the kernel, hypervisor, and trusted services. This breaks the secure boot chain and enables arbitrary code execution at system startup.

Technologies: Barebox. Vendors: Barebox.

Quick answers

Is CVE-2026-33243 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-33243 being exploited in the wild.
How severe is CVE-2026-33243?: High severity, with a CVSS score of 8.2, published 20 March 2026.
Which products and versions are affected?: Barebox 2016.03.0 to before 2026.03.1 (also affects 2025.09.x before 2025.09.3).
Is there a fix for CVE-2026-33243?: A patch was published on 2026-03-17: Patch included in barebox v2026.03.1 and v2025.09.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-33243 attacked?: It is attacked with local access or with physical access, in device firmware.
Am I affected by CVE-2026-33243?: Check whether you run Barebox 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

The vulnerability is a signature verification bypass in the FIT container format. The mkimage(1) tool signs a FIT by hashing selected nodes and stores a list of hashed nodes in the "hashed-nodes" property; however, this property itself is not included in the signature hash. An attacker can modify hashed-nodes to reference different images than those actually signed, causing the bootloader to verify and boot attacker-controlled images instead of the legitimate ones. The attack requires physical or local access to read/write the FIT on storage. Affected versions are 2016.03.0 through 2026.02.0 (patched in 2026.03.1 and backported to 2025.09.3). The fix reconstructs the hashed nodes list from the FIT configuration rather than trusting the hashed-nodes property.

Affected products

barebox barebox 2016.03.0 to before 2026.03.1 (also affects 2025.09.x before 2025.09.3)

Timeline

2026-03-20: disclosed: Public disclosure of CVE-2026-33243
2026-03-17: patched: Patch included in barebox v2026.03.1 and v2025.09.3
2026-03-02: other: Issue reported privately by Apple Security Engineering and Architecture (SEAR)

References

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