CVE-2026-106465

Missing HelloVerifyRequest cookie validation in the NetX Secure DTLS server

Published Oct 14, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603, the NetX Secure DTLS server never compares the cookie a client returns with the one it issued, and treats any non-empty cookie as verified. A remote attacker can make the server send its full handshake flight, several kilobytes, to a forged source address, using it to reflect amplified traffic at a third party.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description The NetX Secure DTLS server sends a HelloVerifyRequest carrying a freshly generated cookie, but never checks the cookie a client returns. The ClientHello parser copies the client's cookie bytes over the value the server issued, and the server then decides whether the client has been verified from the cookie's length alone. A peer that puts any single cookie byte in its first ClientHello skips the verification exchange entirely, so the server has no return-routability check and completes handshakes for forged source addresses. In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603, the NetX Secure DTLS server never compares the cookie a client returns with the one it issued, and treats any non-empty cookie as verified. A remote attacker can make the server send its full handshake flight, several kilobytes, to a forged source address, using it to reflect amplified traffic at a third party.
Title NetX Duo DTLS Server Bypasses Cookie Validation, Enabling Forged Connections Missing HelloVerifyRequest cookie validation in the NetX Secure DTLS server
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L'}

Type Values Removed Values Added
First Time appeared Eclipse
Eclipse netx Duo
Vendors & Products Eclipse
Eclipse netx Duo
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title NetX Duo DTLS Server Bypasses Cookie Validation, Enabling Forged Connections
Type Values Removed Values Added
Description The NetX Secure DTLS server sends a HelloVerifyRequest carrying a freshly generated cookie, but never checks the cookie a client returns. The ClientHello parser copies the client's cookie bytes over the value the server issued, and the server then decides whether the client has been verified from the cookie's length alone. A peer that puts any single cookie byte in its first ClientHello skips the verification exchange entirely, so the server has no return-routability check and completes handshakes for forged source addresses.
Weaknesses CWE-290
CWE-406
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
eclipse
Published
Updated
Nov 4, 2026, 1:23 PM
Reserved
Oct 6, 2026, 4:53 PM
Status
Awaiting Analysis
Published
Oct 14, 2026, 6:17 PM
Modified
Nov 4, 2026, 2:17 PM