CVE-2026-64135

System crash via oversized SMBus block response

Published Jul 19, 2026 · Updated Jul 19, 2026

Stack buffer overflow in the Linux Kernel ADM1266 hwmon driver allows local users to crash the system via an oversized SMBus response. adm1266_nvmem_read_blackbox() gives i2c_smbus_read_block_data() a 5-byte stack buffer, but the helper copies the device-supplied block length of up to 32 bytes before the four-byte-length check runs. Reachability requires an ADM1266 device and an NVMEM blackbox read that returns more than five bytes; the published assessment limits the demonstrated consequence to a system crash.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in the Linux Kernel ADM1266 hwmon driver allows local users to crash the system via an oversized SMBus response. adm1266_nvmem_read_blackbox() gives i2c_smbus_read_block_data() a 5-byte stack buffer, but the helper copies the device-supplied block length of up to 32 bytes before the four-byte-length check runs. Reachability requires an ADM1266 device and an NVMEM blackbox read that returns more than five bytes; the published assessment limits the demonstrated consequence to a system crash.

The record

CVE
CVE-2026-64135
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-120
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=15609d1893020436e1e8ccfd9ded774a96dd17a2 <0dbf64c502443c08c2e28a77ecbfcc5479d93228
  2. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <2b7a698d5093b548c464828d984f05ced5f3fd2a
  3. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <33251abb9c9dd62943be76f0427c5527ee39188f
  4. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <6ed16a40b162e9d87d9ac8bed4d7f0e3e807700e
  5. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <7f705e581ef3e6bb308a121a89adf5237d968204
  6. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <ba09f4baa5bd96c5d26c942defa546a72dbbe5bf
  7. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <ca560f7566df7e2826c2999e959e6b94eb938f76
  8. Affected versionversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <eee213daa1e1b402eb631bcd1b8c5aa340a6b081
  9. Affected versionversion=5.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=15609d1893020436e1e8ccfd9ded774a96dd17a2 <0dbf64c502443c08c2e28a77ecbfcc5479d93228; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <2b7a698d5093b548c464828d984f05ced5f3fd2a; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <33251abb9c9dd62943be76f0427c5527ee39188f; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <6ed16a40b162e9d87d9ac8bed4d7f0e3e807700e; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <7f705e581ef3e6bb308a121a89adf5237d968204; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <ba09f4baa5bd96c5d26c942defa546a72dbbe5bf; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <ca560f7566df7e2826c2999e959e6b94eb938f76; version=15609d1893020436e1e8ccfd9ded774a96dd17a2 <eee213daa1e1b402eb631bcd1b8c5aa340a6b081; version=5.10

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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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