CVE-2026-53042

Local kernel crash via uninitialized fwctl class node

Published Jun 24, 2026 · Updated Jun 24, 2026

Denial of service in the fwctl subsystem of Linux Kernel allows local users to crash the system during CXL device removal. Because CXL initializes before fwctl, device_add() runs before fwctl_class registration, leaving knode_class uninitialized; later device_del() passes that node to klist_del() and dereferences NULL. Reachability requires local low-privileged access and an affected CXL device removal path; the documented consequence is a kernel crash with no confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.12%
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 the fwctl subsystem of Linux Kernel allows local users to crash the system during CXL device removal. Because CXL initializes before fwctl, device_add() runs before fwctl_class registration, leaving knode_class uninitialized; later device_del() passes that node to klist_del() and dereferences NULL. Reachability requires local low-privileged access and an affected CXL device removal path; the documented consequence is a kernel crash with no confidentiality or integrity impact.

The record

CVE
CVE-2026-53042
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-824, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record 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=6.15
  2. Affected versionversion=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <1075f2f590fdac147f8b8010c35b606564b5c7d7
  3. Affected versionversion=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <a28f56988c8e5bb9375806a5cfb0bf54d662ae3f
  4. Affected versionversion=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <a55f80233f384dc89ef3425b2e1dd0e6d44bcf29

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.15; version=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <1075f2f590fdac147f8b8010c35b606564b5c7d7; version=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <a28f56988c8e5bb9375806a5cfb0bf54d662ae3f; version=858ce2f56b5253063f61f6b1c58a6dbf5d71da0b <a55f80233f384dc89ef3425b2e1dd0e6d44bcf29

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-824Access of Uninitialized Pointer
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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