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NVD / CVE Program· CNA Linux

CVE-2026-64373: cpufreq: Fix hotplug-suspend race during reboot

Noroxi assessment

Priority: Monitor (action score 18/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.08% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 4.10, 4.15, 4.20; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.

Low priority for now. Upgrade to Linux Linux 4.10, 4.15, 4.20; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: cpufreq: Fix hotplug-suspend race during reboot During system reboot, cpufreq_suspend() is called via the kernel_restart() -> device_shutdown() path. Unlike the normal system suspend path, the reboot path does not call freeze_processes(), so userspace processes and kernel threads remain active. This allows CPU hotplug operations to run concurrently with cpufreq_suspend(). The original code has no synchronization with CPU hotplug, leading to a race condition where governor_data can be freed by the hotplug path while cpufreq_suspend() is still accessing it, resulting in a null pointer dereference: Unable to handle kernel NULL pointer dereference Call Trace: do_kernel_fault+0x28/0x3c cpufreq_suspend+0xdc/0x160 device_shutdown+0x18/0x200 kernel_restart+0x40/0x80 arm64_sys_reboot+0x1b0/0x200 Fix this by adding cpus_read_lock()/cpus_read_unlock() to cpufreq_suspend() to block CPU hotplug operations while suspend is in progress. [ rjw: Changelog edits ]

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Jul 25, 2026
Updated
Nov 6, 2026
EPSS
0.0% · 0th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.0%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.4.198 and later · before 4.5
  • linux linux kernel4.9.198 and later · before 4.10
  • linux linux kernel4.14.151 and later · before 4.15
  • linux linux kernel4.19.81 and later · before 4.20
  • linux linux kernel5.3.8 and later · before 5.4
  • linux linux kernel5.4.1 and later · before 5.10.261
  • linux linux kernel5.11 and later · before 5.15.212
  • linux linux kernel5.16 and later · before 6.1.178
  • linux linux kernel6.2 and later · before 6.6.145
  • linux linux kernel6.7 and later · before 6.12.96
  • linux linux kernel6.13 and later · before 6.18.39
  • linux linux kernel6.19 and later · before 7.1.4
  • linux linux kernel5.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 8bfa06ea6e81bf08d2132d7e70c2b5313b34caf8, 7ccf3b8b7a12dc9da158c2e699c36d04b2496944, 5f466713989250938624afa79dc33bae20920700, 89ab39da1452d272007acc5912d4008047b86706, cb4b4601f910c78d2b49f637a12ef98b41cb76a9, 5.4affected
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before 6d5dd354c37abaf4d60400c55c71f23ba2b33639affected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before 9103078c7b3091a2fbb52af176f95982ee7dd7f8affected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before cd4524ff6567fa4458a5bec4b017105e671d393eaffected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before 73255d702c7560185fd5951aadcf7eb057c2f453affected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before a0ef2fc89d28ca62923376c4b8ffaa57136a36beaffected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before 6e175c00c62dca3d91b987015808b5d52e8db2b4affected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before a0106b41f9a724868d390b8b3b4ea5ca0e04ea53affected · git
    • 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 and later · before a9029dd55696c651ee46912afa2a166fa456bb3eaffected · git
    • 4.4.198 and later · before 4.5affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.96-16.12.96-1
Debian:14linuxbefore 7.1.4-17.1.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64371Jul 25, 2026 · proc: protect ptrace_may_access() with exec_update_lock (part 1)
    22Monitor
  • ← EarlierCVE-2026-64372Jul 25, 2026 · cpufreq: pcc: fix use-after-free and double free in _OSC evaluation
    31Monitor
  • Later →CVE-2026-64374Jul 25, 2026 · sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux4.10Vendor (CNA)
Linux Linux4.15Vendor (CNA)
Linux Linux4.20Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux5.4Vendor (CNA)
Linux Linux6d5dd354c37abaf4d60400c55c71f23ba2b33639Vendor (CNA)
Linux Linux6e175c00c62dca3d91b987015808b5d52e8db2b4Vendor (CNA)
Linux Linux73255d702c7560185fd5951aadcf7eb057c2f453Vendor (CNA)
Linux Linux9103078c7b3091a2fbb52af176f95982ee7dd7f8Vendor (CNA)
Linux Linuxa0106b41f9a724868d390b8b3b4ea5ca0e04ea53Vendor (CNA)
Linux Linuxa0ef2fc89d28ca62923376c4b8ffaa57136a36beVendor (CNA)
Linux Linuxa9029dd55696c651ee46912afa2a166fa456bb3eVendor (CNA)
Linux Linuxcd4524ff6567fa4458a5bec4b017105e671d393eVendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records