CVE-2025-40261

Kernel crash via deferred-work use-after-free

Published Dec 4, 2025 · Updated Aug 5, 2026

Race condition in the nvme-fc host driver in affected Linux and Siemens firmware allows attackers to crash the kernel during teardown. nvme_fc_delete_ctrl() cancels ioerr_work before nvme_fc_delete_association(), so an I/O error can requeue the work and access the freed controller. Reaching the race requires an NVMe-over-Fabrics Fibre Channel association whose teardown overlaps queued error work, causing list corruption and a kernel BUG.

CVSS severity9.8
Critical
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the nvme-fc host driver in affected Linux and Siemens firmware allows attackers to crash the kernel during teardown. nvme_fc_delete_ctrl() cancels ioerr_work before nvme_fc_delete_association(), so an I/O error can requeue the work and access the freed controller. Reaching the race requires an NVMe-over-Fabrics Fibre Channel association whose teardown overlaps queued error work, causing list corruption and a kernel BUG.

The record

CVE
CVE-2025-40261
Published
Dec 4, 2025
Updated
Aug 5, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-1341
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=V3.1.5 <*
  2. Affected versionversion=V3.1.6 <*

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*; version=V3.1.6 <*
The Linux Kernel Organization · Linuxversion=19fce0470f05031e6af36e49ce222d0f0050d432 <0a2c5495b6d1ecb0fa18ef6631450f391a888256; version=19fce0470f05031e6af36e49ce222d0f0050d432 <33f64600a12055219bda38b55320c62cdeda9167; version=19fce0470f05031e6af36e49ce222d0f0050d432 <48ae433c6cc6985f647b1b37d8bb002972cf9bdb; version=19fce0470f05031e6af36e49ce222d0f0050d432 <9610a2c162ef729a3988213a4604376e492f6f44; version=19fce0470f05031e6af36e49ce222d0f0050d432 <a9b1315ed428239612601e9e188329e7cefa32fd; version=19fce0470f05031e6af36e49ce222d0f0050d432 <fbd5741a556eaaa63d0908132ca79d335b58b1cd; version=5.10.9 <5.10.253; version=5.11; version=f1cd8c40936ff2b560e1f35159dd6a4602b558e5 <3f48cd7f35da07fc067cef926bb7f6f4735de37b
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.5 <*; version=V3.1.6 <*
Siemens · RUGGEDCOM RST2428Pversion=0 <V4.0
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.5 <*; version=V3.1.6 <*

Published CVSS scores

6.6Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
6.6Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
9.8Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1341Multiple Releases of Same Resource or Handle

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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