CVE-2026-102719

NetX Secure DTLS server issues predictable HelloVerifyRequest cookies, so a spoofed client can pass the return-routability check

Published Sep 29, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the NetX Secure DTLS server fills HelloVerifyRequest cookies from NX_RAND(), by default the C library rand(), with no key and no binding to the client. An attacker who can predict the generator's output can pass the cookie exchange from a spoofed address and make the server send its handshake flight to a victim, using it as a traffic reflector.

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
Weaknesses CWE-330
Type Values Removed Values Added
Description Predictable DTLS HelloVerifyRequest Cookie in NetX Secure In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, the NetX Secure DTLS server fills HelloVerifyRequest cookies from NX_RAND(), by default the C library rand(), with no key and no binding to the client. An attacker who can predict the generator's output can pass the cookie exchange from a spoofed address and make the server send its handshake flight to a victim, using it as a traffic reflector.
Title Predictable DTLS HelloVerifyRequest Cookie in NetX Secure NetX Secure DTLS server issues predictable HelloVerifyRequest cookies, so a spoofed client can pass the return-routability check
Weaknesses CWE-338
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/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 netxduo
Vendors & Products Eclipse
Eclipse netxduo
Type Values Removed Values Added
Title Predictable DTLS HelloVerifyRequest Cookie in NetX Secure
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Predictable DTLS HelloVerifyRequest Cookie in NetX Secure
Weaknesses CWE-330
References
Metrics cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
eclipse
Published
Updated
Nov 4, 2026, 9:36 AM
Reserved
Sep 29, 2026, 4:15 PM
Status
Awaiting Analysis
Published
Sep 29, 2026, 6:17 PM
Modified
Nov 4, 2026, 10:17 AM