Physical code disclosure and execution via QSPI oracle
Published Sep 7, 2026 · Updated Sep 10, 2026
Information disclosure in encrypted XIP on Nordic Semiconductor nRF5340 allows physically proximate attackers to recover and inject code. The AES-CTR decryptor accepts malleated QSPI ciphertext without authentication, while a self-loop instruction creates an observable bus oracle that recovers plaintext two bytes at a time. Exploitation requires bench-level access to substitute and monitor external flash; it can disclose flash contents and bypass secure boot to execute injected code.
Summary
What happened
Information disclosure in encrypted XIP on Nordic Semiconductor nRF5340 allows physically proximate attackers to recover and inject code. The AES-CTR decryptor accepts malleated QSPI ciphertext without authentication, while a self-loop instruction creates an observable bus oracle that recovers plaintext two bytes at a time. Exploitation requires bench-level access to substitute and monitor external flash; it can disclose flash contents and bypass secure boot to execute injected code.
The record
- CVE
- CVE-2026-18796
- Published
- Sep 7, 2026
- Updated
- Sep 10, 2026
- Vendor
- Nordic Semiconductor ASA
- Product
- nRF5340
- Classifications
- CWE-1342, CAPEC-37
- Attack vector
- physical
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 7, 2026CVE publishedPublication date reported by the CVE source.
- Sep 10, 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?
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- Affected versionversion=All build codes
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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