CVE-2026-43038Network attack vector

Remote kernel memory corruption via stale control buffer

Published May 1, 2026 · Updated May 1, 2026

Type confusion in affected Linux Kernel releases allows remote attackers to corrupt kernel memory via crafted ICMPv4 error packets. The ip6_err_gen_icmpv6_unreach function clones an IPv4 error skb without clearing its control buffer, so icmp6_send reinterprets IPv4 inet_skb_parm state as inet6_skb_parm and follows an attacker-set destination-option offset. Reachability requires an IPv6-over-IPv4/SIT or IPv6 GRE tunnel endpoint with IPv6 MIP6 support; the resulting out-of-bounds 16-byte swap can disclose or overwrite adjacent skb metadata and crash the kernel.

CVSS severity9.8
Critical
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in affected Linux Kernel releases allows remote attackers to corrupt kernel memory via crafted ICMPv4 error packets. The ip6_err_gen_icmpv6_unreach function clones an IPv4 error skb without clearing its control buffer, so icmp6_send reinterprets IPv4 inet_skb_parm state as inet6_skb_parm and follows an attacker-set destination-option offset. Reachability requires an IPv6-over-IPv4/SIT or IPv6 GRE tunnel endpoint with IPv6 MIP6 support; the resulting out-of-bounds 16-byte swap can disclose or overwrite adjacent skb metadata and crash the kernel.

The record

CVE
CVE-2026-43038
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-843, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=3.13
  2. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <0452b6526b2f54b2413b9cb4ff1ea2ac542c99c7
  3. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <1ceeebd5bd6d855b17a5df625109bfe29129d7cf
  4. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <3d5127d998de617b130aae96b138dba22ac6a8a7
  5. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <86ab3e55673a7a49a841838776f1ab18d23a67b5
  6. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <a2edbb6393972a02114b6003953a5cef3104fada
  7. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <a4437faf135da293d16fcc4cc607316742bd0ebb
  8. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <c438ba010171b70bad22fc18b1d5bdc3627476e8
  9. Affected versionversion=ca15a078bd907df5fc1c009477869c5cbde3b753 <e41953e7d118e2702bcb217879c173d9d1d3cd4e

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.13; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <0452b6526b2f54b2413b9cb4ff1ea2ac542c99c7; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <1ceeebd5bd6d855b17a5df625109bfe29129d7cf; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <3d5127d998de617b130aae96b138dba22ac6a8a7; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <86ab3e55673a7a49a841838776f1ab18d23a67b5; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <a2edbb6393972a02114b6003953a5cef3104fada; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <a4437faf135da293d16fcc4cc607316742bd0ebb; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <c438ba010171b70bad22fc18b1d5bdc3627476e8; version=ca15a078bd907df5fc1c009477869c5cbde3b753 <e41953e7d118e2702bcb217879c173d9d1d3cd4e

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1190Exploit Public-Facing Application

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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