CVE-2026-64521

Privileged debugfs hang via recursive mutex acquisition

Published Jul 25, 2026 · Updated Jul 25, 2026

Deadlock in the Amlogic A4 pin controller in Linux Kernel 6.15 allows local users to hang a pinconf-pins debugfs read. pinconf_pins_show() holds pctldev->mutex before the Amlogic A4 driver calls pinctrl_find_gpio_range_from_pin(), which reacquires that mutex. High local privileges and access to the controller's debugfs entry are required; the self-deadlock hangs that read path without a reported host crash or reboot.

CVSS severity4.4
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

Deadlock in the Amlogic A4 pin controller in Linux Kernel 6.15 allows local users to hang a pinconf-pins debugfs read. pinconf_pins_show() holds pctldev->mutex before the Amlogic A4 driver calls pinctrl_find_gpio_range_from_pin(), which reacquires that mutex. High local privileges and access to the controller's debugfs entry are required; the self-deadlock hangs that read path without a reported host crash or reboot.

The record

CVE
CVE-2026-64521
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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=6.15
  2. Affected versionversion=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <744ac926c0e55267a10b49b5b72582afef4ad49f
  3. Affected versionversion=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <e72ce029810390eb987a036fb2c8a5da9a23b685
  4. Affected versionversion=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <e917713f013423069782ff554935c7a5d4266783

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.15; version=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <744ac926c0e55267a10b49b5b72582afef4ad49f; version=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <e72ce029810390eb987a036fb2c8a5da9a23b685; version=6e9be3abb78c2f6c97a51070004a5165702f0ed9 <e917713f013423069782ff554935c7a5d4266783

Published CVSS scores

4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
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

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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