CVE-2026-33243
barebox: FIT Signature Verification Bypass Vulnerability
Description
barebox is a bootloader. In barebox from version 2016.03.0 to before version 2026.03.1 (and the corresponding backport to 2025.09.3), an attacker could exploit a FIT signature verification vulnerability to trick the bootloader into booting different images than those that were verified as part of a signed configuration. mkimage(1) sets the hashed-nodes property of the FIT signature node to list which nodes of the FIT were hashed as part of the signing process as these will need to be verified later on by the bootloader. However, hashed-nodes itself is not part of the hash and could therefore be modified to allow booting different images than those that have been verified. This issue has been patched in barebox versions 2026.03.1 and backported to 2025.09.3.
INFO
Published Date :
March 20, 2026, 11:16 p.m.
Last Modified :
March 26, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update barebox to version 2025.09.3 or later.
- Update barebox to version 2026.03.1 or later.
- Ensure image integrity verification is properly configured.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-33243.
| URL | Resource |
|---|---|
| https://github.com/barebox/barebox/commit/aca01795056d51060cb096f9a1ea309361743e05 | Patch |
| https://github.com/barebox/barebox/security/advisories/GHSA-3fvj-q26p-j6h4 | Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33243 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-33243
weaknesses.
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-2026-33243 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33243 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Mar. 26, 2026
Action Type Old Value New Value Changed Description barebox is a bootloader. In barebox from version 2016.03.0 to before version 2025.09.3 and from version 2025.10.0 to before version 2026.03.1, when creating a FIT, mkimage(1) sets the hashed-nodes property of the FIT signature node to list which nodes of the FIT were hashed as part of the signing process as these will need to be verified later on by the bootloader. However, hashed-nodes itself is not part of the hash and can therefore be modified by an attacker to trick the bootloader into booting different images than those that have been verified. This issue has been patched in barebox versions 2025.09.3 and 2026.03.1. barebox is a bootloader. In barebox from version 2016.03.0 to before version 2026.03.1 (and the corresponding backport to 2025.09.3), an attacker could exploit a FIT signature verification vulnerability to trick the bootloader into booting different images than those that were verified as part of a signed configuration. mkimage(1) sets the hashed-nodes property of the FIT signature node to list which nodes of the FIT were hashed as part of the signing process as these will need to be verified later on by the bootloader. However, hashed-nodes itself is not part of the hash and could therefore be modified to allow booting different images than those that have been verified. This issue has been patched in barebox versions 2026.03.1 and backported to 2025.09.3. -
Initial Analysis by [email protected]
Mar. 25, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:* versions from (including) 2013.07 up to (excluding) 2026.04 *cpe:2.3:a:denx:u-boot:2026.04:rc1:*:*:*:*:*:* *cpe:2.3:a:denx:u-boot:2026.04:rc2:*:*:*:*:*:* *cpe:2.3:a:denx:u-boot:2026.04:rc3:*:*:*:*:*:* *cpe:2.3:a:pengutronix:barebox:*:*:*:*:*:*:*:* versions from (including) 2016.03.0 up to (excluding) 2025.09.3 *cpe:2.3:a:pengutronix:barebox:*:*:*:*:*:*:*:* versions from (including) 2025.10.0 up to (excluding) 2026.03.1 Added Reference Type GitHub, Inc.: https://github.com/barebox/barebox/commit/aca01795056d51060cb096f9a1ea309361743e05 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/barebox/barebox/security/advisories/GHSA-3fvj-q26p-j6h4 Types: Patch, Vendor Advisory -
New CVE Received by [email protected]
Mar. 20, 2026
Action Type Old Value New Value Added Description barebox is a bootloader. In barebox from version 2016.03.0 to before version 2025.09.3 and from version 2025.10.0 to before version 2026.03.1, when creating a FIT, mkimage(1) sets the hashed-nodes property of the FIT signature node to list which nodes of the FIT were hashed as part of the signing process as these will need to be verified later on by the bootloader. However, hashed-nodes itself is not part of the hash and can therefore be modified by an attacker to trick the bootloader into booting different images than those that have been verified. This issue has been patched in barebox versions 2025.09.3 and 2026.03.1. Added CVSS V3.1 AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H Added CWE CWE-345 Added Reference https://github.com/barebox/barebox/commit/aca01795056d51060cb096f9a1ea309361743e05 Added Reference https://github.com/barebox/barebox/security/advisories/GHSA-3fvj-q26p-j6h4