CVE-2026-23103

IPv6 address-state corruption via per-device locking race

Published Feb 4, 2026 · Updated Feb 4, 2026

Improper locking in Linux Kernel allows local users to corrupt ipvlan IPv6 address state through concurrent address changes. The shared port address table is protected by separate per-device addrs_lock instances, while ipvlan_open() and ipvlan_close() also omit the required lock. Triggering requires simultaneous address changes on two CPUs through the IPv6 notifier, producing a false-negative busy check or inconsistent address-hash state.

CVSS severity7.8
High
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in Linux Kernel allows local users to corrupt ipvlan IPv6 address state through concurrent address changes. The shared port address table is protected by separate per-device addrs_lock instances, while ipvlan_open() and ipvlan_close() also omit the required lock. Triggering requires simultaneous address changes on two CPUs through the IPv6 notifier, producing a false-negative busy check or inconsistent address-hash state.

The record

CVE
CVE-2026-23103
Published
Feb 4, 2026
Updated
Feb 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 4, 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=4.17
  2. Affected versionversion=8230819494b3bf284ca7262ac5f877333147b937 <04ba6de6eff61238e5397c14ac26a6578c7735a5
  3. Affected versionversion=8230819494b3bf284ca7262ac5f877333147b937 <1f300c10d92c547c3a7d978e1212ff52f18256ed
  4. Affected versionversion=8230819494b3bf284ca7262ac5f877333147b937 <6a81e2db096913d7e43aada1c350c1282e76db39
  5. Affected versionversion=8230819494b3bf284ca7262ac5f877333147b937 <d3ba32162488283c0a4c5bedd8817aec91748802

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.17; version=8230819494b3bf284ca7262ac5f877333147b937 <04ba6de6eff61238e5397c14ac26a6578c7735a5; version=8230819494b3bf284ca7262ac5f877333147b937 <1f300c10d92c547c3a7d978e1212ff52f18256ed; version=8230819494b3bf284ca7262ac5f877333147b937 <6a81e2db096913d7e43aada1c350c1282e76db39; version=8230819494b3bf284ca7262ac5f877333147b937 <d3ba32162488283c0a4c5bedd8817aec91748802

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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking
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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