CVE-2025-39809

Kernel crash via undersized QuickI2C ACPI structures

Published Sep 16, 2025 · Updated Sep 16, 2025

An out-of-bounds write in Linux kernel 6.14 through 6.16.4 causes a kernel crash during Intel QuickI2C controller initialization. quicki2c_acpi_get_dsd_property copies 12-byte ICRS or ISUB data into an 11-byte stack structure because its definition omits the trailing reserved byte. Reachability requires Intel THC QuickI2C hardware whose firmware supplies the affected ACPI _DSD properties; the demonstrated consequence is a kernel crash.

CVSS severity8.4
High
EPSS probability0.15%
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 Linux kernel 6.14 through 6.16.4 causes a kernel crash during Intel QuickI2C controller initialization. quicki2c_acpi_get_dsd_property copies 12-byte ICRS or ISUB data into an 11-byte stack structure because its definition omits the trailing reserved byte. Reachability requires Intel THC QuickI2C hardware whose firmware supplies the affected ACPI _DSD properties; the demonstrated consequence is a kernel crash.

The record

CVE
CVE-2025-39809
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record 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=5282e45ccbfa91524944a32d40386c54fdd4d145 <1db9df89a213318a48d958385dc1b17b379dc32b
  2. Affected versionversion=5282e45ccbfa91524944a32d40386c54fdd4d145 <4adce86d4b13d15dec7810967839b931b1598700
  3. Affected versionversion=6.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5282e45ccbfa91524944a32d40386c54fdd4d145 <1db9df89a213318a48d958385dc1b17b379dc32b; version=5282e45ccbfa91524944a32d40386c54fdd4d145 <4adce86d4b13d15dec7810967839b931b1598700; version=6.14

Published CVSS scores

8.4LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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