CVE-2026-89561Public exploit

Kernel crash via raced IPv6 device dereference

Published Sep 11, 2026 · Updated Sep 11, 2026

NULL-pointer dereference in Linux IPv6 RPL routing allows attackers to crash the kernel during concurrent MTU changes and packet receipt. ipv6_rpl_srh_rcv() reads idev->cnf.rpl_seg_enabled without checking whether __in6_dev_get() returned NULL after addrconf_ifdown() cleared dev->ip6_ptr. Triggering requires RPL source-routing traffic to reach an interface while a privileged operation lowers its MTU below 1280; the resulting dereference can interrupt the host.

CVSS severityUnavailable
Unscored
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in Linux IPv6 RPL routing allows attackers to crash the kernel during concurrent MTU changes and packet receipt. ipv6_rpl_srh_rcv() reads idev->cnf.rpl_seg_enabled without checking whether __in6_dev_get() returned NULL after addrconf_ifdown() cleared dev->ip6_ptr. Triggering requires RPL source-routing traffic to reach an interface while a privileged operation lowers its MTU below 1280; the resulting dereference can interrupt the host.

The record

CVE
CVE-2026-89561
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=5.7
  2. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c
  3. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <eab3a917cdcb182542a3aac6a0d2d30659ca9821
  4. Affected versionversion=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <f826df95332c07380206dbd54178b6eefb311aba

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <63f50e9f90d0287ad66a0955ebfc2d3a9c044a1c; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <eab3a917cdcb182542a3aac6a0d2d30659ca9821; version=8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 <f826df95332c07380206dbd54178b6eefb311aba

Published CVSS scores

No CVSS assessment is available in this record.

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 exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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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