How severe is CVE-2026-33243?

CVE-2026-33243 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-33243 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33243?

CVE-2026-33243 primarily affects Denx U-boot. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-33243?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33243 have an EU (EUVD) identifier?

Yes. CVE-2026-33243 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13893.

When was CVE-2026-33243 published?

CVE-2026-33243 was published on 2026-03-20 and last updated on 2026-06-17.

CVE-2026-33243

CVE-2026-33243 is a high-severity vulnerability in Denx U-boot with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13893
Weakness: CWE-345
Affected product: Denx U-boot
Published: 2026-03-20
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-33243?: 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.
How severe is CVE-2026-33243?: CVE-2026-33243 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-33243 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33243?: CVE-2026-33243 primarily affects Denx U-boot. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-33243?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33243 have an EU (EUVD) identifier?: Yes. CVE-2026-33243 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13893.
When was CVE-2026-33243 published?: CVE-2026-33243 was published on 2026-03-20 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*:*

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