CVE-2026-108930: Netcore NR268 Information Disclosure Flaw

CVE-2026-108930 Overview

CVE-2026-108930 is an information disclosure vulnerability in the Netcore NR268 router running firmware version 1.7.121109. The flaw resides in the ddns_wan_list_show function within the ddns_wan_list_show.cgi file, part of the Dynamic DNS (DDNS) Handler component. Manipulating the user_idN and passwordN arguments causes the handler to disclose stored DDNS credentials. The issue is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor. The exploit has been publicly disclosed, and the vendor did not respond to disclosure attempts.

Critical Impact
Authenticated remote attackers can retrieve stored DDNS usernames and passwords from affected Netcore NR268 devices, enabling account takeover of third-party DDNS services.

Affected Products

Netcore NR268 router
Firmware version 1.7.121109
DDNS Handler component (ddns_wan_list_show.cgi)

Discovery Timeline

2026-10-12 - CVE-2026-108930 published to NVD
2026-10-13 - Last updated in NVD database

Technical Details for CVE-2026-108930

Vulnerability Analysis

The vulnerability is an information disclosure flaw in the DDNS management interface of the Netcore NR268 router. When a request is made to ddns_wan_list_show.cgi, the ddns_wan_list_show function returns DDNS configuration data that includes the user_idN and passwordN fields in plaintext. These fields contain the credentials used to authenticate the router against third-party DDNS providers.

Exploitation requires network reachability to the router's management interface and existing high-privilege access, as reflected in the attack requirements. Once accessed, the handler emits the credentials in the response body without masking or redaction. According to the public report on GitHub, the leaked values can be used to hijack the associated DDNS account.

Root Cause

The root cause is the inclusion of sensitive credential material in the server-side response rendered by ddns_wan_list_show. The CGI handler does not sanitize or omit secret fields before serializing the DDNS configuration list. Any user able to invoke the handler receives the full credential payload.

Attack Vector

The attack is remote and executed over the network against the router's web management interface. An attacker who can reach ddns_wan_list_show.cgi and supply valid session credentials can issue a GET request to retrieve the DDNS user list, parse the response, and extract the user_idN and passwordN values for each configured provider.

No verified exploit code is published for this entry; the mechanism is documented in the GitHub disclosure report and the VulDB entry.

Detection Methods for CVE-2026-108930

Indicators of Compromise

HTTP GET requests to /ddns_wan_list_show.cgi on the router's management interface from unexpected source addresses.
Response bodies from the router containing user_idN or passwordN parameter names returned to clients.
Authentication failures or unexpected logins at configured DDNS providers (No-IP, DynDNS, etc.) tied to the router's credentials.

Detection Strategies

Inspect web server and reverse proxy logs for access patterns targeting ddns_wan_list_show.cgi, especially from outside the trusted management subnet.
Alert when the router's HTTP management port is reachable from WAN or untrusted VLANs.
Correlate DDNS provider login events with router administrator activity to detect credential reuse by third parties.

Monitoring Recommendations

Capture netflow and HTTP metadata for traffic to router management endpoints and retain for post-incident review.
Monitor for configuration changes on the router that follow access to ddns_wan_list_show.cgi.
Track outbound DNS updates to DDNS providers and flag updates originating from IP addresses that do not match the router's WAN address.

How to Mitigate CVE-2026-108930

Immediate Actions Required

Restrict the Netcore NR268 web management interface to a trusted management VLAN and block WAN-side access.
Rotate any DDNS provider credentials configured on affected routers and enable provider-side multi-factor authentication where available.
Change the router administrator password, since the vulnerability requires authenticated access that may already be compromised.

Patch Information

No vendor patch is available. The disclosure record notes that Netcore was contacted but did not respond. Monitor the VulDB entry for CVE-2026-108930 for updates on vendor remediation.

Workarounds

Disable the DDNS feature on the router and use an external DDNS client running on a separate, hardened host.
Place the router behind an upstream firewall that restricts HTTP/HTTPS access to the management interface by source IP.
Replace the device with a supported router if the vendor continues to be unresponsive to security disclosures.

bash

# Example firewall rule to restrict router management access to an admin subnet
iptables -A INPUT -i wan0 -p tcp --dport 80 -j DROP
iptables -A INPUT -i lan0 -s 192.168.10.0/24 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP