CVE-2023-53291

Kernel service interrupt via lingering rcuscale threads

Published Sep 16, 2025 · Updated Sep 16, 2025

Denial of service in affected Linux kernel branches allows local users to trigger a kernel oops by unloading the rcuscale module. The rcu_scale_cleanup() path leaves kfree_scale_thread workers running after module code is removed, so a worker later fetches an instruction from an unmapped address. Triggering the fault requires privileged module management and the kfree_rcu_test test mode; the resulting oops can panic or otherwise interrupt the host.

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

Denial of service in affected Linux kernel branches allows local users to trigger a kernel oops by unloading the rcuscale module. The rcu_scale_cleanup() path leaves kfree_scale_thread workers running after module code is removed, so a worker later fetches an instruction from an unmapped address. Triggering the fault requires privileged module management and the kfree_rcu_test test mode; the resulting oops can panic or otherwise interrupt the host.

The record

CVE
CVE-2023-53291
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.6
  2. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <1dd7547c7610723b2b6afe1a3c4ddb2bde63387c
  3. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <23fc8df26dead16687ae6eb47b0561a4a832e2f6
  4. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <29b1da4f90fc42c91beb4e400d926194925ad31b
  5. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <604d6a5ff718874904b0fe614878a42b42c0d699
  6. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <b8a6ba524d41f4da102e65f90498d9a910839621
  7. Affected versionversion=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <f766d45ab294871a3d588ee76c666852f151cad9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.6; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <1dd7547c7610723b2b6afe1a3c4ddb2bde63387c; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <23fc8df26dead16687ae6eb47b0561a4a832e2f6; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <29b1da4f90fc42c91beb4e400d926194925ad31b; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <604d6a5ff718874904b0fe614878a42b42c0d699; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <b8a6ba524d41f4da102e65f90498d9a910839621; version=e6e78b004fa7e0ab455d46d27f218bf6ce178a18 <f766d45ab294871a3d588ee76c666852f151cad9

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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.

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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

T1499Endpoint Denial of Service

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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