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CVE-2026-33243· NVD / CVE Program· CNA GitHub_M

barebox: FIT Signature Verification Bypass Vulnerability

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.2 · v3.1—No exploit No fix recorded
Published
Mar 20, 2026
Updated
Sep 11, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-33243

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
pengutronixbarebox

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • pengutronix barebox2016.03.0 and later · before 2025.09.3
  • pengutronix barebox2025.10.0 and later · before 2026.03.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • barebox barebox

    • >= 2016.03.0, < 2025.09.3, >= 2025.10.0, < 2026.03.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:11u-bootfrom 0—

Same product

pengutronix: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-15938Pengutronix barebox through 2019.08.1 has a remote buffer overflow in nfs_readlink_req in fs/nfs.c because a length field is directly used f
    40Plan
  • CVE-2019-15937Pengutronix barebox through 2019.08.1 has a remote buffer overflow in nfs_readlink_reply in net/nfs.c because a length field is directly use
    40Plan
  • CVE-2020-13910Pengutronix Barebox through v2020.05.0 has an out-of-bounds read in nfs_read_reply in net/nfs.c because a field of an incoming network packe
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2024-57261Feb 18, 2025 · In barebox before 2025.01.0, request2size in common/dlmalloc.c has an integer overflow, a related issue to CVE-2024-57258.
    28Monitor
  • ← EarlierCVE-2024-57262Feb 18, 2025 · In barebox before 2025.01.0, ext4fs_read_symlink has an integer overflow for zalloc (adding one to an le32 variable) via a crafted ext4 file
    28Monitor
  • Later →CVE-2026-34960May 11, 2026 · barebox Out-of-Bounds Read in DHCP Option Parsing
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-345 · Insufficient Verification of Data Authenticity

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records