# CVE-2026-90680: D-Link DIR-823G stack buffer overflow in SetStaticRouteSettings

Source: https://junglewise.ai/threats/cve-2026-90680-d-link-dir-823g-stack-buffer-overflow-in-setstaticroutesettings  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-14. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-90680 · Severity: critical · CVSS 9.9 · Published 2026-09-14

D-Link DIR-823G is a wireless router used in home and small office networks. A remote attacker can send specially crafted XML requests to the router's web management interface that overflow internal memory buffers, causing the web service to crash and potentially enabling arbitrary code execution on the device.

Technologies: [D-Link DIR-823G](https://junglewise.ai/threats/technologies/dir-823g). Vendors: [D-Link](https://junglewise.ai/threats/vendors/d-link).

## Quick answers

**Is CVE-2026-90680 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90680 being exploited in the wild.

**How severe is CVE-2026-90680?** Critical severity, with a CVSS score of 9.9, published 14 September 2026.

**Which products and versions are affected?** D-Link DIR-823G 1.0.2B05_20181207.

**Is there a fix for CVE-2026-90680?** 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-2026-90680 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-90680?** Check whether you run D-Link DIR-823G 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 stack-based buffer overflow (CWE-121) in the HNAP1 SetStaticRouteSettings handler. The vulnerable component uses unbounded strcpy() calls to copy XML field values (IPAddress, SubnetMask, Gateway) into fixed 32-byte stack buffers without length validation. An attacker can send oversized values in these XML fields via an HTTP POST request to /HNAP1/SetStaticRouteSettings to trigger memory corruption. No authentication is required; the attack is remotely exploitable from the network. Successful exploitation causes crashes of the web management process and potentially allows code execution. A patch is not yet known to be available.

## Affected products

- D-Link DIR-823G 1.0.2B05_20181207

## Timeline

- 2026-09-14: disclosed

## References

- [https://github.com/Amalll-Sec/router-vulnerability-research/blob/main/advisories/d-link/dir-823g/SetStaticRouteSettings/README.md](https://github.com/Amalll-Sec/router-vulnerability-research/blob/main/advisories/d-link/dir-823g/SetStaticRouteSettings/README.md)
- [https://vuldb.com/cve/CVE-2026-90680](https://vuldb.com/cve/CVE-2026-90680)

## Related threats

- [D-Link DIR-823G privilege escalation in web interface](https://junglewise.ai/threats/cve-2026-15270-d-link-dir-823g-privilege-escalation-in-web-interface)
- [D-Link DIR-823G privilege escalation in vsftpd.conf](https://junglewise.ai/threats/cve-2026-11492-d-link-dir-823g-privilege-escalation-in-vsftpd-conf)
- [D-Link DIR-823G command injection in timelycheck and sysconf binaries](https://junglewise.ai/threats/cve-2025-60671-d-link-dir-823g-command-injection-in-timelycheck-and-sysconf)