CVE-2025-39958

Kernel warning via failed s390 IOMMU attach

Published Oct 9, 2025 · Updated Oct 9, 2025

Fault-handling failure in Linux kernel 6.2 through 6.16.8 allows local users to trigger a kernel warning via surprise PCI hot removal. s390_iommu_attach_device propagates zpci_register_ioat's invalid-handle condition after the hypervisor has fenced the removed device, violating a no-fail default-domain attach invariant. The path is limited to s390 zPCI teardown or probe during surprise removal; published evidence establishes the warning but not privilege gain, data access, or a crash.

CVSS severity7.8
High
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

Fault-handling failure in Linux kernel 6.2 through 6.16.8 allows local users to trigger a kernel warning via surprise PCI hot removal. s390_iommu_attach_device propagates zpci_register_ioat's invalid-handle condition after the hypervisor has fenced the removed device, violating a no-fail default-domain attach invariant. The path is limited to s390 zPCI teardown or probe during surprise removal; published evidence establishes the warning but not privilege gain, data access, or a crash.

The record

CVE
CVE-2025-39958
Published
Oct 9, 2025
Updated
Oct 9, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 9, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <359613f2fa009587154511e4842e8ab9532edd15
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9ffaf5229055fcfbb3b3d6f1c7e58d63715c3f73

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <359613f2fa009587154511e4842e8ab9532edd15; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9ffaf5229055fcfbb3b3d6f1c7e58d63715c3f73

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

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

No sourced classifications are available.

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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