# CVE-2026-79911: TOTOLINK N600R stack-based buffer overflow in setSystemConfig

Source: https://junglewise.ai/threats/cve-2026-79911-totolink-n600r-stack-based-buffer-overflow-in-setsystemconfig  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-79911 · Severity: critical · CVSS 10 · Published 2026-08-25

TOTOLINK N600R is a wireless router used to provide internet connectivity in homes and small offices. A stack-based buffer overflow vulnerability in the router's web configuration interface allows an attacker to crash the device or execute arbitrary code by sending a specially crafted hostname parameter, potentially giving complete control over the router and any networks it serves.

Technologies: [TOTOLINK N600r](https://junglewise.ai/threats/technologies/n600r). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-79911 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-79911 being exploited in the wild.

**How severe is CVE-2026-79911?** Critical severity, with a CVSS score of 10, published 25 August 2026.

**Which products and versions are affected?** TOTOLINK N600r 4.3.0cu.7647_B20210106.

**Is there a fix for CVE-2026-79911?** 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-2026-79911 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-79911?** Check whether you run TOTOLINK N600r 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 in the setSystemConfig function of the CGI handler (/cgi-bin/cstecgi.cgi) in TOTOLINK N600R firmware version 4.3.0cu.7647_B20210106. The vulnerable code does not properly validate the length of the Hostname argument before copying it into a fixed-size stack buffer, allowing an attacker to overflow the buffer. The attack requires network access to the router's web interface and can be executed without authentication. A successful exploit allows remote code execution with the privileges of the CGI process, potentially leading to complete device compromise.

## Affected products

- TOTOLINK N600R 4.3.0cu.7647_B20210106

## Timeline

- 2026-08-25: disclosed: Vulnerability publicly disclosed
- 2026-08-25: other: Exploit code publicly available on GitHub

## References

- [https://github.com/dxz0069/WAVLINK-WN530H4-Command-Injection-in-set_add_routing/blob/main/TOTOLINK_N600R_cstecgi_strcpy_sprintf_Multi_Function_Stack_Overflow.md](https://github.com/dxz0069/WAVLINK-WN530H4-Command-Injection-in-set_add_routing/blob/main/TOTOLINK_N600R_cstecgi_strcpy_sprintf_Multi_Function_Stack_Overflow.md)
- [https://vuldb.com/cve/CVE-2026-79911](https://vuldb.com/cve/CVE-2026-79911)

## Related threats

- [TOTOLINK N600R insufficient randomness in session token generation](https://junglewise.ai/threats/cve-2026-82555-totolink-n600r-insufficient-randomness-in-session-token)
- [TOTOLINK N600R command injection in cstecgi.cgi](https://junglewise.ai/threats/cve-2026-79912-totolink-n600r-command-injection-in-cstecgi-cgi)
- [TOTOLINK N600R command injection in setWiFiWpsConfig](https://junglewise.ai/threats/cve-2025-51390-totolink-n600r-command-injection-in-setwifiwpsconfig)