CVE-2026-76856 is a cross-site request forgery vulnerability affecting Netcore NR255-V firmware version 1.5.130703. The vulnerability impacts the wan_config_set_cgi, wan_num_set_cgi, and lan_ip_change_cgi endpoints, enabling attackers to craft malicious requests that, when executed by an authenticated administrator, modify WAN or LAN network configurations without their consent. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, user interaction required, and high impact on confidentiality and integrity.

Successful exploitation could allow an attacker to alter critical network configuration settings on the affected device without administrator consent, potentially disrupting network operations or redirecting traffic. The vulnerability requires the administrator to be authenticated and interact with a malicious request, limiting the attack scope but still posing a significant risk to network integrity.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, administrators should avoid interacting with untrusted web content while logged into the device's management interface and consider additional network-level protections to restrict access to the device's administrative interface.