CyberSecBulletin
CVE-2026-33243NVD status: Analyzed

barebox: Insufficient Verification of Data Authenticity

CVE-2026-33243 is a high-severity insufficient verification of data authenticity vulnerability in barebox, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. Affected barebox versions: >= 2016.03.0, < 2025.09.3; >= 2025.10.0, < 2026.03.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.11% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of barebox you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Bareboxbarebox>= 2016.03.0, < 2025.09.3; >= 2025.10.0, < 2026.03.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (github.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

More Insufficient Verification of Data Authenticity vulnerabilities (CWE-345)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in barebox

All barebox vulnerabilities

Recent Insufficient Verification of Data Authenticity vulnerabilities

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