CVE-2026-13216

Kernel stack corruption via unvalidated device capability length

Published Aug 25, 2026 · Updated Aug 25, 2026

An out-of-bounds write in the virtio PCI driver in Zephyr RTOS 4.2.0 through 4.4.1 allows attackers to corrupt kernel stack memory. virtio_pci_read_cap() trusts the device-supplied cap_len after a production-disabled assertion, then uses it to calculate a copy loop into fixed-size stack buffers. An untrusted virtio PCIe device or hostile backend must supply the capability during boot-time probe, enabling kernel code execution or a crash.

CVSS severity6.1
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in the virtio PCI driver in Zephyr RTOS 4.2.0 through 4.4.1 allows attackers to corrupt kernel stack memory. virtio_pci_read_cap() trusts the device-supplied cap_len after a production-disabled assertion, then uses it to calculate a copy loop into fixed-size stack buffers. An untrusted virtio PCIe device or hostile backend must supply the capability during boot-time probe, enabling kernel code execution or a crash.

The record

CVE
CVE-2026-13216
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-787, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=4.2.0 <4.4.2

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Zephyr Project · Zephyr RTOSversion=4.2.0 <4.4.2

Published CVSS scores

6.1Zephyr ProjectCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/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-787Out-of-bounds Write
T1200Hardware Additions

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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