CVE-2026-23003Network attack vector

Remote crash via unprepared VLAN encapsulation

Published Jan 25, 2026 · Updated Jan 25, 2026

Uninitialized-memory use in the Linux Kernel allows remote attackers to crash IPv6 tunnel endpoints with crafted VLAN-encapsulated packets. The __ip6_tnl_rcv function uses pskb_inet_may_pull without preparing VLAN headers, so ECN decapsulation reads uninitialized packet-buffer data. Reachability requires an exposed IPv6 tunnel or GRE endpoint; the published impact is a service-interrupting kernel crash without data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-memory use in the Linux Kernel allows remote attackers to crash IPv6 tunnel endpoints with crafted VLAN-encapsulated packets. The __ip6_tnl_rcv function uses pskb_inet_may_pull without preparing VLAN headers, so ECN decapsulation reads uninitialized packet-buffer data. Reachability requires an exposed IPv6 tunnel or GRE endpoint; the published impact is a service-interrupting kernel crash without data disclosure or modification.

The record

CVE
CVE-2026-23003
Published
Jan 25, 2026
Updated
Jan 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 25, 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=350a6640fac4b53564ec20aa3f4a0922cb0ba5e6
  2. Affected versionversion=6.8
  3. Affected versionversion=8d975c15c0cd744000ca386247432d57b21f9df0 <81c734dae203757fb3c9eee6f9896386940776bd
  4. Affected versionversion=8d975c15c0cd744000ca386247432d57b21f9df0 <b9f915340f25cae1562f18e1eb52deafca328414
  5. Affected versionversion=8d975c15c0cd744000ca386247432d57b21f9df0 <df5ffde9669314500809bc498ae73d6d3d9519ac
  6. Affected versionversion=a9bc32879a08f23cdb80a48c738017e39aea1080
  7. Affected versionversion=af6b5c50d47ab43e5272ad61935d0ed2e264d3f0
  8. Affected versionversion=c835df3bcc14858ae9b27315dd7de76370b94f3a
  9. Affected versionversion=d54e4da98bbfa8c257bdca94c49652d81d18a4d8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=350a6640fac4b53564ec20aa3f4a0922cb0ba5e6; version=6.8; version=8d975c15c0cd744000ca386247432d57b21f9df0 <81c734dae203757fb3c9eee6f9896386940776bd; version=8d975c15c0cd744000ca386247432d57b21f9df0 <b9f915340f25cae1562f18e1eb52deafca328414; version=8d975c15c0cd744000ca386247432d57b21f9df0 <df5ffde9669314500809bc498ae73d6d3d9519ac; version=a9bc32879a08f23cdb80a48c738017e39aea1080; version=af6b5c50d47ab43e5272ad61935d0ed2e264d3f0; version=c835df3bcc14858ae9b27315dd7de76370b94f3a; version=d54e4da98bbfa8c257bdca94c49652d81d18a4d8

Published CVSS scores

7.5Linux kernel security teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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