Out-of-bounds write in NetX Duo - CVE-2026-103416
Published: November 9, 2026
Vulnerability identifier: #VU162957
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-103416
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated remote attacker to crash a NetX Duo TLS client or corrupt its session data.
The vulnerability exists due to an unchecked copy into NetX Secure's fixed-size handshake cache when TLS 1.3 is explicitly enabled with ECC ciphersuites and a HelloRetryRequest produces an oversized ClientHello. An unauthenticated remote attacker can control or impersonate the client's server and send an oversized cookie to trigger the out-of-bounds write before certificate authentication.
Affected software
NetX Duo
How to mitigate CVE-2026-103416
Install security update from vendor's website.
NetX Duo - update to 6.5.2.202603