CVE-2026-8369

Packet injection via fixed IPv4 header offset

Published May 13, 2026 · Updated May 13, 2026

Improper input validation in OpenThread before commit 26a882d allows attackers on an adjacent IPv4 network to inject malformed IPv6 packets. The NAT64 translator assumes a 20-byte IPv4 header, so packets with options shift transport-header parsing and leave option bytes in the translated payload. NAT64 must be enabled and the attacker must share the IPv4 infrastructure link; crafted LSRR or SSRR options also evade mandatory source-route rejection, enabling integrity loss and limited service interruption.

CVSS severity6.0
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in OpenThread before commit 26a882d allows attackers on an adjacent IPv4 network to inject malformed IPv6 packets. The NAT64 translator assumes a 20-byte IPv4 header, so packets with options shift transport-header parsing and leave option bytes in the translated payload. NAT64 must be enabled and the attacker must share the IPv4 infrastructure link; crafted LSRR or SSRR options also evade mandatory source-route rejection, enabling integrity loss and limited service interruption.

The record

CVE
CVE-2026-8369
Published
May 13, 2026
Updated
May 13, 2026
Vendor
OpenThread
Product
OpenThread
Classifications
CWE-20
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 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?

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  1. Affected versionversion=commit 26a882d

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

OpenThread · OpenThreadversion=commit 26a882d

Published CVSS scores

6.0Google Inc.CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation

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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