CVE-2025-39872

Kernel memory corruption via unlocked HSR lookup

Published Sep 23, 2025 · Updated Sep 23, 2025

Use-after-free in Linux HSR networking allows local users to corrupt kernel memory by racing an HSR port lookup with device teardown. The hsr_get_port_ndev function traverses the HSR port list without an RCU read lock and returns a net_device without taking a reference. Local low-privileged access and an active HSR interface are required; reuse of the stale device object compromises kernel confidentiality, integrity, and availability.

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 Linux HSR networking allows local users to corrupt kernel memory by racing an HSR port lookup with device teardown. The hsr_get_port_ndev function traverses the HSR port list without an RCU read lock and returns a net_device without taking a reference. Local low-privileged access and an active HSR interface are required; reuse of the stale device object compromises kernel confidentiality, integrity, and availability.

The record

CVE
CVE-2025-39872
Published
Sep 23, 2025
Updated
Sep 23, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

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

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=6.14
  2. Affected versionversion=9c10dd8eed74de9e8adeb820939f8745cd566d4a <68a6729afd3e8e9a2a32538642ce92b96ccf9b1d
  3. Affected versionversion=9c10dd8eed74de9e8adeb820939f8745cd566d4a <847748fc66d08a89135a74e29362a66ba4e3ab15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.14; version=9c10dd8eed74de9e8adeb820939f8745cd566d4a <68a6729afd3e8e9a2a32538642ce92b96ccf9b1d; version=9c10dd8eed74de9e8adeb820939f8745cd566d4a <847748fc66d08a89135a74e29362a66ba4e3ab15

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS: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 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

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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