CVE-2026-12051

Device crash via null DFU download buffer

Published Aug 11, 2026 · Updated Aug 11, 2026

NULL pointer dereference in USB DFU in Zephyr RTOS 4.4.0 through 4.4.2 allows physically proximate attackers to crash devices. The device_next handle_download() path dereferences buf->len and buf->data when a zero-length DFU_DNLOAD request reaches it without a Data OUT buffer. Exploitation requires enabled DFU download support, a registered image, and a prior transition to DFU_DNLOAD_IDLE; the consequence is limited to device availability.

CVSS severity4.6
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in USB DFU in Zephyr RTOS 4.4.0 through 4.4.2 allows physically proximate attackers to crash devices. The device_next handle_download() path dereferences buf->len and buf->data when a zero-length DFU_DNLOAD request reaches it without a Data OUT buffer. Exploitation requires enabled DFU download support, a registered image, and a prior transition to DFU_DNLOAD_IDLE; the consequence is limited to device availability.

The record

CVE
CVE-2026-12051
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-476, T1499
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 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.

  1. Affected versionversion=4.4.0 <4.5.0

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=4.4.0 <4.5.0

Published CVSS scores

4.6Zephyr ProjectCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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