# CVE-2026-76856: Netcore NR255-V cross-site request forgery in network configuration endpoints

Source: https://junglewise.ai/threats/cve-2026-76856-netcore-nr255-v-cross-site-request-forgery-in-network  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-15. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-76856 · Severity: high · CVSS 8.1 · Published 2026-09-15

The Netcore NR255-V is a wireless router used to provide internet connectivity in home and small office networks. This vulnerability allows an attacker to trick a logged-in administrator into unknowingly changing critical network settings (WAN or LAN configuration) by visiting a malicious webpage. An attacker could disrupt internet service, redirect traffic, or isolate the network from legitimate access.

Technologies: [Netcore NR255-V](https://junglewise.ai/threats/technologies/nr255-v). Vendors: [Netcore](https://junglewise.ai/threats/vendors/netcore).

## Quick answers

**Is CVE-2026-76856 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76856 being exploited in the wild.

**How severe is CVE-2026-76856?** High severity, with a CVSS score of 8.1, published 15 September 2026.

**Which products and versions are affected?** Netcore NR255-V 1.5.130703.

**Is there a fix for CVE-2026-76856?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-76856 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-76856?** Check whether you run Netcore NR255-V at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Netcore NR255-V firmware 1.5.130703 contains a cross-site request forgery (CSRF) vulnerability in the wan_config_set_cgi, wan_num_set_cgi, and lan_ip_change_cgi endpoints. These endpoints lack proper CSRF protection (such as anti-CSRF tokens), allowing attackers to craft forged HTTP requests that execute with the privileges of an authenticated administrator. The attack requires that an administrator be logged into the router's web interface and be tricked into visiting a malicious webpage controlled by the attacker. A successful exploit enables unauthorized modification of WAN and LAN configuration settings, potentially disrupting network connectivity or redirecting traffic. Netcore has not released a patch as of the advisory date.

## Affected products

- Netcore NR255-V 1.5.130703

## Timeline

- 2026-09-15: disclosed: CVE-2026-76856 published on NVD
- 2026-09-04: other: Public reference published on GitHub by researchers Zhou Ao, Yin Luxing, Jiang Yuxuan, Liu Xin, @Nebusec

## References

- [https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-csrf-wan-reconfig.md](https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-csrf-wan-reconfig.md)
- [https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-cross-site-request-forgery-in-wan-lan-configuration-endpoints](https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-cross-site-request-forgery-in-wan-lan-configuration-endpoints)

## Related threats

- [Netcore NR255-V stored cross-site scripting in L7 content management](https://junglewise.ai/threats/cve-2026-92257-netcore-nr255-v-stored-cross-site-scripting-in-l7-content)
- [Netcore NR255-V sensitive information disclosure in VPN configuration handlers](https://junglewise.ai/threats/cve-2026-92256-netcore-nr255-v-sensitive-information-disclosure-in-vpn)
- [Netcore NR255-V out-of-bounds read in filter_arp_put_file.cgi](https://junglewise.ai/threats/cve-2026-92255-netcore-nr255-v-out-of-bounds-read-in-filter-arp-put-file-cgi)
- [Netcore NR255-V stored cross-site scripting in DHCP and ARP hostname fields](https://junglewise.ai/threats/cve-2026-76873-netcore-nr255-v-stored-cross-site-scripting-in-dhcp-and-arp)
- [Netcore NR255-V stored cross-site scripting in DHCP and ACL management](https://junglewise.ai/threats/cve-2026-76872-netcore-nr255-v-stored-cross-site-scripting-in-dhcp-and-acl)