CVE-2025-39871

Kernel memory corruption via duplicate device release

Published Sep 23, 2025 · Updated Sep 23, 2025

Use-after-free in the Linux idxd dmaengine driver allows local users to corrupt kernel memory by unloading an affected kernel module. idxd_remove calls idxd_unregister_devices, whose device_unregister path already performs put_device, then calls idxd_free and releases the same device reference again. The trigger requires CAP_SYS_MODULE or root access to unbind the PCI device, and delayed cleanup under CONFIG_DEBUG_KOBJECT_RELEASE can turn the refcount underflow into kernel memory corruption.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux idxd dmaengine driver allows local users to corrupt kernel memory by unloading an affected kernel module. idxd_remove calls idxd_unregister_devices, whose device_unregister path already performs put_device, then calls idxd_free and releases the same device reference again. The trigger requires CAP_SYS_MODULE or root access to unbind the PCI device, and delayed cleanup under CONFIG_DEBUG_KOBJECT_RELEASE can turn the refcount underflow into kernel memory corruption.

The record

CVE
CVE-2025-39871
Published
Sep 23, 2025
Updated
Sep 23, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 23, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 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=21f9f5cd9a0c75084d4369ba0b8c4f695c41dea7 <dd7a7e43269711d757fc260b0bbdf7138f75de11
  2. Affected versionversion=2b7a961cea0e5b65afda911f76d14fec5c98d024
  3. Affected versionversion=6.15
  4. Affected versionversion=68ac5a01f635b3791196fd1c39bc48497252c36f
  5. Affected versionversion=d2d05fd0fc95c4defed6f7b87550e20e8baa1d97 <0e95ee7f532b21206fe3f1c4054002b0d21e3b9c
  6. Affected versionversion=d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 <da4fbc1488a4cec6748da685181ee4449a878dac
  7. Affected versionversion=d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 <f41c538881eec4dcf5961a242097d447f848cda6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=21f9f5cd9a0c75084d4369ba0b8c4f695c41dea7 <dd7a7e43269711d757fc260b0bbdf7138f75de11; version=2b7a961cea0e5b65afda911f76d14fec5c98d024; version=6.15; version=68ac5a01f635b3791196fd1c39bc48497252c36f; version=d2d05fd0fc95c4defed6f7b87550e20e8baa1d97 <0e95ee7f532b21206fe3f1c4054002b0d21e3b9c; version=d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 <da4fbc1488a4cec6748da685181ee4449a878dac; version=d5449ff1b04dfe9ed8e455769aa01e4c2ccf6805 <f41c538881eec4dcf5961a242097d447f848cda6

Published CVSS scores

5.5OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8CanonicalCVSS: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

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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.

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Technologies

Your stack

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Your stack

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