CVE-2025-40089

Local kernel crash via missing CXL feature check

Published Oct 30, 2025 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel 6.15 through 6.17.4 and 6.18-rc1 allows local users to crash the kernel. cxl_feature_info() dereferences a NULL cxlfs pointer when CXL EDAC requests feature information from hardware with no Features support. Reachability requires local low-privileged access and affected CXL hardware; the resulting kernel oops interrupts the system.

CVSS severity6.8
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

NULL pointer dereference in the Linux kernel 6.15 through 6.17.4 and 6.18-rc1 allows local users to crash the kernel. cxl_feature_info() dereferences a NULL cxlfs pointer when CXL EDAC requests feature information from hardware with no Features support. Reachability requires local low-privileged access and affected CXL hardware; the resulting kernel oops interrupts the system.

The record

CVE
CVE-2025-40089
Published
Oct 30, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 30, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=eb5dfcb9e36d0e46089fec777d911313c1876fa3 <a375246fcf2bbdaeb1df7fa7ee5a8b884a89085e
  3. Affected versionversion=eb5dfcb9e36d0e46089fec777d911313c1876fa3 <b8a69e3b1a460bf5d96dd53cbd121aa2cd346886

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.15; version=eb5dfcb9e36d0e46089fec777d911313c1876fa3 <a375246fcf2bbdaeb1df7fa7ee5a8b884a89085e; version=eb5dfcb9e36d0e46089fec777d911313c1876fa3 <b8a69e3b1a460bf5d96dd53cbd121aa2cd346886

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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