U BootApplication · Denx

CVE-2026-33243

HIGH · 8.2 CVSS v3.1 Published 2026-03-20
Fix available
A fix is available. Upgrade to 2025.09.3 / 2026.03.1 or later.
See remediation →
84/100
Remediation priority · High
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
U BootApplication
Affected:>= 2013.07, < 2026.04= 2026.04
BareboxApplication
Affected:>= 2016.03.0, < 2025.09.3>= 2025.10.0, < 2026.03.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2025.09.3 / 2026.03.1 / 2026.04 or later
Fixed in 2025.09.32026.03.12026.04
Vendor patch github.com →
Recommended fix High confidence

barebox 2026.03.1 (or 2025.09.3 for backported fix)

  1. 1. Identify the currently running barebox version using 'barebox-version' or checking /etc/version
  2. 2. Determine which stable branch is applicable to your environment: 2025.09.3 (backport) or 2026.03.1 (current stable)
  3. 3. Obtain the fixed barebox release from the official repository: https://github.com/barebox/barebox/releases
  4. 4. Rebuild your barebox image with the fixed version, ensuring FIT image signing uses the patched mkimage tool
  5. 5. Verify the fix by checking that hashed-nodes property is now included in the hash computation during signature verification
  6. 6. Update the bootloader on affected devices with the new patched version
Caveat Ensure your firmware/boot infrastructure supports the new barebox version; may require adjustments to FIT image signing workflows

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33243 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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