CVE-2026-31847

Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23. This exposes a privileged diagnostic interface that is not intended for external access and can be used to interact with the underlying system.

More information : https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zip