NVD security advisoryHigh
High advisory for A remotely exploitable denial-of-service
CVE-2026-120596 · Reported 2 Nov 2026
Full advisory details, affected packages, severity context, and original source.
Affected technology
A remotely exploitable denial-of-serviceAffected product
Advisory overview
A remotely exploitable denial-of-service vulnerability exists in the TCP options parser of the Nut/Net TCP/IP stack included in Nut/OS, developed by Ethernut/Egnite. Nut/OS releases up to version 5.1 are affected. An unauthenticated attacker can send a single TCP segment containing an unknown TCP option with a length byte of zero to any open TCP port on a vulnerable device. When processed, this malformed option triggers an infinite loop in the function NutTcpInputOptions, permanently blocking the TCP processing thread and rendering all TCP-based services unresponsive until the device is rebooted.