# CVE-2026-76865: Netcore NR255-V null pointer dereference in QoS handlers

Source: https://junglewise.ai/threats/cve-2026-76865-netcore-nr255-v-null-pointer-dereference-in-qos-handlers  
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-2026-76865 · Severity: medium · CVSS 4.9 · Published 2026-09-15

The Netcore NR255-V is a wireless router used in home and small office networks. A flaw in its QoS (Quality of Service) configuration handlers allows a remote attacker with administrative credentials to send specially crafted requests that crash the router's web interface, causing a temporary service outage until the device is rebooted.

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

## Quick answers

**Is CVE-2026-76865 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-76865 being exploited in the wild.

**How severe is CVE-2026-76865?** Medium severity, with a CVSS score of 4.9, published 15 September 2026.

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

**Is there a fix for CVE-2026-76865?** 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-2026-76865 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-76865?** 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 a null pointer dereference (CWE-476) in the QoS setter CGI handlers filter_conn_del_cgi.c and gre_prio_set_cgi.c, caused by unchecked return values from atoi() function calls. When atoi() fails to convert input strings to integers, it returns 0 without indication of failure; the subsequent code dereferences these unvalidated values without null checks. An attacker with administrative access to the router's web interface can supply malformed input to trigger the null pointer dereference, causing a denial of service. The vulnerability affects NR255-V firmware version 1.5.130703; 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-null-deref-atoi.md](https://github.com/draw-ctf/netcore-router-public-refs/blob/main/2026.08.19-netcore-nr255v-null-deref-atoi.md)
- [https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-null-pointer-dereference-via-unchecked-atoi-in-qos-setter-handlers](https://www.vulncheck.com/advisories/netcore-nr255-v-1.5.130703-null-pointer-dereference-via-unchecked-atoi-in-qos-setter-handlers)

## 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)