# CVE-2026-5975: Totolink A7100RU CGI cstecgi.cgi setDmzCfg os command injection

> Remote attackers can execute arbitrary OS commands on Totolink A7100RU routers via the setDmzCfg function in cstecgi.cgi.

- **Severity:** Critical 9.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Apr 2026
- **Updated:** 9 Apr 2026
- **Also known as:** GHSA-v89g-prph-7892

## What is CVE-2026-5975?

CVE-2026-5975 is a critical command injection vulnerability in Totolink A7100RU, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was identified in Totolink A7100RU 7.4cu.2313_b20191024. The impacted element is the function setDmzCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Such manipulation of the argument wanIdx leads to os command injection. The attack may be performed from remote. The exploit is publicly available and might be used.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-5975?


## How do I fix CVE-2026-5975?

No fix has been published for CVE-2026-5975 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5975 being exploited?

There is no known exploitation of CVE-2026-5975 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5975 and fix it if it is affected.

What it is: CVE-2026-5975 is a critical command injection vulnerability in Totolink A7100RU, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5975 in the wild and no public exploit code.

Affected product: Totolink A7100RU. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5975/ (Markdown: https://insights.sbomify.com/CVE-2026-5975/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5975
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5975
- OSV: https://osv.dev/vulnerability/CVE-2026-5975

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5975/
Summaries are generated and may contain mistakes; the official description above is the record.