CVE-2026-106465: Eclipse ThreadX NetX Secure vulnerability
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.
Affected Software
Event History
Frequently Asked Questions
What does an attacker need to bypass the verification step?
The attacker only needs to include any single cookie byte in its first ClientHello. The server treats the non-empty cookie as verification without checking whether it matches the cookie it issued.
Which deployments are affected by the missing check?
Deployments operating the NetX Secure DTLS server are affected because the server can complete handshakes without confirming that the client can receive traffic at its claimed source address.
What security property is lost if this is exploited?
The DTLS server no longer performs a return-routability check before completing a handshake. An attacker can therefore initiate handshakes using forged source addresses.