Executive brief
The Netcore NR255-V is a residential network router used to connect devices to the internet. This vulnerability allows an attacker on the local network to inject malicious scripts through DHCP hostname fields, which are later displayed in the router's web management interface. If a network administrator views the affected pages, their browser could execute the attacker's script, potentially allowing unauthorized access to router settings or theft of administrative credentials.
Technical details
This is a stored cross-site scripting (XSS) vulnerability in the DHCP dynamic IP display and ARP bind list display components of the web management interface. The vulnerability exists in the hostname field handling code (dhcp_dynamicip_show_cgi.c and arp_bind_list_show_cgi.c), which fails to properly sanitize user-controlled input before rendering it via network_config.js and network_security.js. An attacker with access to the local network (adjacent network vector) can inject arbitrary HTML and JavaScript through hostname fields in DHCP or ARP traffic. When a network administrator accesses the web interface to view these pages, the injected script executes in their browser context. No patch availability is currently documented in the advisory materials.
Affected products
- Netcore NR255-V 1.5.130703
Timeline
- 2026-09-04: disclosed
- 2026-09-15: advisory