CVE-2026-64191

Local kernel compromise via oversized I2C block transfer

Published Jul 20, 2026 · Updated Jul 20, 2026

Out-of-bounds access in the Linux Kernel i2c-stub driver allows local users to corrupt or disclose kernel memory through an I2C ioctl. stub_xfer() trusts data->block[0] above the 32-byte limit and copies past the stack-resident i2c_smbus_data.block buffer because its direct smbus_xfer path bypasses validation. The nondefault i2c-stub module must be loaded with chip_addr, and the attacker needs access to its /dev/i2c-* node; exploitation can disclose kernel-stack data, panic the host, or execute kernel code.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in the Linux Kernel i2c-stub driver allows local users to corrupt or disclose kernel memory through an I2C ioctl. stub_xfer() trusts data->block[0] above the 32-byte limit and copies past the stack-resident i2c_smbus_data.block buffer because its direct smbus_xfer path bypasses validation. The nondefault i2c-stub module must be loaded with chip_addr, and the attacker needs access to its /dev/i2c-* node; exploitation can disclose kernel-stack data, panic the host, or execute kernel code.

The record

CVE
CVE-2026-64191
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 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=2.6.33
  2. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <0526931b16e5a118d367b7bfce7d797e63f7ac69
  3. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <1c4ffe6b4f04365485ed58d64c9bb86b46fc9037
  4. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <21e87f336ac6303fed54a69b1d0d79a23b25c8d0
  5. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <3fd225f3e4cd67ec8ddab1afed9da03c7c43537c
  6. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <4bd8635f28c135a08aac6badcd7d9b5cdb34335f
  7. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <5f4d2bd028ebb6e4c09a9d64842546022321d4a7
  8. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e
  9. Affected versionversion=4710317891e4824ce1510a6b5066abbd3e917750 <7e9072dbd5f2f17934751873450d2c22080ead80

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.33; version=4710317891e4824ce1510a6b5066abbd3e917750 <0526931b16e5a118d367b7bfce7d797e63f7ac69; version=4710317891e4824ce1510a6b5066abbd3e917750 <1c4ffe6b4f04365485ed58d64c9bb86b46fc9037; version=4710317891e4824ce1510a6b5066abbd3e917750 <21e87f336ac6303fed54a69b1d0d79a23b25c8d0; version=4710317891e4824ce1510a6b5066abbd3e917750 <3fd225f3e4cd67ec8ddab1afed9da03c7c43537c; version=4710317891e4824ce1510a6b5066abbd3e917750 <4bd8635f28c135a08aac6badcd7d9b5cdb34335f; version=4710317891e4824ce1510a6b5066abbd3e917750 <5f4d2bd028ebb6e4c09a9d64842546022321d4a7; version=4710317891e4824ce1510a6b5066abbd3e917750 <6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e; version=4710317891e4824ce1510a6b5066abbd3e917750 <7e9072dbd5f2f17934751873450d2c22080ead80

Published CVSS scores

7.8kernel.orgCVSS: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 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-125Out-of-bounds Read
T1068Exploitation for Privilege Escalation

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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