CVE-2026-43198Network attack vector

Unspecified impact via partially initialized child socket

Published May 6, 2026 · Updated May 6, 2026

Race condition in Linux Kernel TCP connection handling allows remote attackers to cause unspecified impact via IPv4-mapped IPv6 connections. tcp_v6_syn_recv_sock() exposes a child socket in the TCP ehash before tcp_v6_mapped_child_init() replaces the inherited listener pinet6 pointer. Exploitation requires triggering the mapped IPv6 child-creation path during the narrow interval before another CPU accesses the partially initialized socket.

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

What happened

Race condition in Linux Kernel TCP connection handling allows remote attackers to cause unspecified impact via IPv4-mapped IPv6 connections. tcp_v6_syn_recv_sock() exposes a child socket in the TCP ehash before tcp_v6_mapped_child_init() replaces the inherited listener pinet6 pointer. Exploitation requires triggering the mapped IPv6 child-creation path during the narrow interval before another CPU accesses the partially initialized socket.

The record

CVE
CVE-2026-43198
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-821
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

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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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7178e2a8027423b2af17ab95df73a749a5b72e5b
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <858d2a4f67ff69e645a43487ef7ea7f28f06deae
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fe89b2f05b854847784f91127319172945c1fadd
  4. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7178e2a8027423b2af17ab95df73a749a5b72e5b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <858d2a4f67ff69e645a43487ef7ea7f28f06deae; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fe89b2f05b854847784f91127319172945c1fadd; version=2.6.12

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-821Incorrect Synchronization

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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