CVE-2026-43099Network attack vector

Kernel crash via unchecked IPv6 lookup error

Published May 6, 2026 · Updated May 6, 2026

Null-pointer dereference in affected Linux Kernel releases allows remote attackers to crash the kernel via an ICMP Extended Echo request. The icmp_build_probe() path passes an ERR_PTR(-EAFNOSUPPORT) result from ipv6_dev_find() to dev_hold() without rejecting the failed lookup. Exploitation requires CONFIG_IPV6=m with the IPv6 module unloaded and a valid IPv6 interface identifier, interrupting the entire host.

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

Null-pointer dereference in affected Linux Kernel releases allows remote attackers to crash the kernel via an ICMP Extended Echo request. The icmp_build_probe() path passes an ERR_PTR(-EAFNOSUPPORT) result from ipv6_dev_find() to dev_hold() without rejecting the failed lookup. Exploitation requires CONFIG_IPV6=m with the IPv6 module unloaded and a valid IPv6 interface identifier, interrupting the entire host.

The record

CVE
CVE-2026-43099
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 2026Record 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=5.13
  2. Affected versionversion=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <47a8bf52156ac7e7a581eca31c1f964ba4258d4d
  3. Affected versionversion=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <5b9911582d441f72fe6ccb15ffe3303bbc07f6f5
  4. Affected versionversion=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <6be325206850a0891896d38bcf83a09d8b54ec48
  5. Affected versionversion=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <f91b3ed9e7fa82a70511b5f6901c88379acf2964
  6. Affected versionversion=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <fde29fd9349327acc50d19a0b5f3d5a6c964dfd8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.13; version=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <47a8bf52156ac7e7a581eca31c1f964ba4258d4d; version=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <5b9911582d441f72fe6ccb15ffe3303bbc07f6f5; version=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <6be325206850a0891896d38bcf83a09d8b54ec48; version=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <f91b3ed9e7fa82a70511b5f6901c88379acf2964; version=d329ea5bd8845f0b196bf41b18b6173340d6e0e4 <fde29fd9349327acc50d19a0b5f3d5a6c964dfd8

Published CVSS scores

7.5LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
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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