# CVE-2026-5178: Totolink A3300R cstecgi.cgi setIptvCfg command injection

> Remote attackers can execute arbitrary commands on Totolink A3300R routers via the setIptvCfg function in cstecgi.cgi.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 31 Mar 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-w3qx-79f2-f95x

## What is CVE-2026-5178?

CVE-2026-5178 is a medium-severity command injection vulnerability in Totolink A3300r Firmware, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A security vulnerability has been detected in Totolink A3300R 17.0.0cu.557_b20221024. Affected by this issue is the function setIptvCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument vlanPriLan3 leads to command injection. Remote exploitation of the attack is possible. The exploit has been disclosed publicly and may be used.

Weakness: CWE-77 (Improper Neutralization of Special Elements used in a Command), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-5178?

It affects 1 product.


Products: Totolink A3300r Firmware.

## How do I fix CVE-2026-5178?

No fix has been published for CVE-2026-5178 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5178 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5178 exists.

## Other vulnerabilities in Totolink A3300r Firmware

- [CVE-2026-31175](https://insights.sbomify.com/CVE-2026-31175/): Command injection in n/a (critical 9.8)
- [CVE-2026-31177](https://insights.sbomify.com/CVE-2026-31177/): Command injection in n/a (critical 9.8)
- [CVE-2026-31178](https://insights.sbomify.com/CVE-2026-31178/): Command injection in n/a (critical 9.8)
- [CVE-2026-31181](https://insights.sbomify.com/CVE-2026-31181/): Command injection in n/a (critical 9.8)
- [CVE-2026-31170](https://insights.sbomify.com/CVE-2026-31170/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5178 and fix it if it is affected.

What it is: CVE-2026-5178 is a medium-severity command injection vulnerability in Totolink A3300r Firmware, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5178 exists.

Affected product: Totolink A3300r Firmware. 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-2026-5178/ (Markdown: https://insights.sbomify.com/CVE-2026-5178/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5178
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5178
- OSV: https://osv.dev/vulnerability/CVE-2026-5178

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5178/
Summaries are generated and may contain mistakes; the official description above is the record.