CVE-2026-46021

Local service interruption via unlocked governor teardown

Published May 27, 2026 · Updated May 27, 2026

Use-after-free in the Linux Kernel thermal core allows local users to interrupt service through concurrent sysfs governor updates. The thermal_zone_device_unregister() path calls thermal_set_governor() without holding the thermal-zone lock, allowing a governor update to race with teardown and access freed memory. Exploitation requires local low-privileged access and precise timing, and the bounded impact is interruption of the affected system.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux Kernel thermal core allows local users to interrupt service through concurrent sysfs governor updates. The thermal_zone_device_unregister() path calls thermal_set_governor() without holding the thermal-zone lock, allowing a governor update to race with teardown and access freed memory. Exploitation requires local low-privileged access and precise timing, and the bounded impact is interruption of the affected system.

The record

CVE
CVE-2026-46021
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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
  2. Affected versionversion=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <37a430a2d4e66ec8238da6c7f7e48809bf265e13
  3. Affected versionversion=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <41ff66baf81c6541f4f985dd7eac4494d03d9440
  4. Affected versionversion=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <64d4ebf91d082034bbc5ae3ba2d7fd800bc02d06
  5. Affected versionversion=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <75f8f3c3e09122270986de9d7aa347d701676761
  6. Affected versionversion=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <f412e541d25a3dfaf3d53e012ade6ff03cae8a45

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.2; version=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <37a430a2d4e66ec8238da6c7f7e48809bf265e13; version=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <41ff66baf81c6541f4f985dd7eac4494d03d9440; version=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <64d4ebf91d082034bbc5ae3ba2d7fd800bc02d06; version=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <75f8f3c3e09122270986de9d7aa347d701676761; version=e33df1d2f3a0141cd79e770f31999ba0dd7ebfa8 <f412e541d25a3dfaf3d53e012ade6ff03cae8a45

Published CVSS scores

5.5NIST NVDCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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