Boot-image replacement via unhashed verification metadata
Published Mar 20, 2026 · Updated Mar 20, 2026
Signature verification bypass in barebox 2016.03.0 through 2025.09.2 and 2025.10.0 through 2026.03.0 allows local users to boot unverified FIT images. The FIT verifier in common/image-fit.c treats the unhashed hashed-nodes property as authoritative, allowing that list and a referenced image to be replaced without invalidating the signature. Exploitation requires local or physical read/write access to FIT storage on a system using signed FIT; the payload inherits the original image's privileges and generally compromises the kernel.
Summary
What happened
Signature verification bypass in barebox 2016.03.0 through 2025.09.2 and 2025.10.0 through 2026.03.0 allows local users to boot unverified FIT images. The FIT verifier in common/image-fit.c treats the unhashed hashed-nodes property as authoritative, allowing that list and a referenced image to be replaced without invalidating the signature. Exploitation requires local or physical read/write access to FIT storage on a system using signed FIT; the payload inherits the original image's privileges and generally compromises the kernel.
The record
- CVE
- CVE-2026-33243
- Published
- Mar 20, 2026
- Updated
- Mar 20, 2026
- Vendor
- Pengutronix
- Product
- barebox
- Classifications
- CWE-345, T1542.003
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Mar 20, 2026CVE publishedPublication date reported by the CVE source.
- Mar 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 2016.03.0, < 2025.09.3
- Affected versionversion=>= 2025.10.0, < 2026.03.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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