# CVE-2026-76857: Netcore NR255-V plaintext DDNS credential disclosure

Source: https://junglewise.ai/threats/cve-2026-76857-netcore-nr255-v-plaintext-ddns-credential-disclosure  
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-2026-76857 · Severity: medium · CVSS 6.5 · Published 2026-09-15

The Netcore NR255-V is a wireless router used in home and small office networks. An authenticated attacker can extract plaintext DDNS account credentials from the router's web interface, leading to compromise of users' dynamic DNS accounts and potential redirection of traffic to attacker-controlled systems.

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

## Quick answers

**Is CVE-2026-76857 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76857 being exploited in the wild.

**How severe is CVE-2026-76857?** Medium severity, with a CVSS score of 6.5, published 15 September 2026.

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

**Is there a fix for CVE-2026-76857?** 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-2026-76857 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-76857?** 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 vulnerability is an insufficiently protected credentials disclosure (CWE-522) in the ddns_wan_list_show.cgi endpoint and related DDNSset_cgi, IGD_GetCgiHandler, and IGD_CgiCall components. An attacker with authentication to the router's web interface can access these CGI handlers to retrieve plaintext DDNS account credentials. The attack requires network reachability to the router's web interface and valid authentication credentials. Successful exploitation exposes sensitive DDNS account information, which can be used to take over DNS records pointing to the victim's network. No patch information is currently available.

## Affected products

- Netcore NR255-V 1.5.130703

## Timeline

- 2026-09-04: disclosed
- 2026-09-15: advisory

## References

- [https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-ddns-cred-disclosure.md](https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-ddns-cred-disclosure.md)
- [https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-plaintext-ddns-credential-disclosure-via-ddns-wan-list-show-cgi](https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-plaintext-ddns-credential-disclosure-via-ddns-wan-list-show-cgi)

## 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)