# CVE-2026-124059: TOTOLINK CA300-PoE cstecgi.cgi setWiFiWdsAddConfig buffer overflow


- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 7 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-cfx7-8946-rr3x

## What is CVE-2026-124059?

CVE-2026-124059 is a critical vulnerability in TOTOLINK CA300-PoE, published on 7 Nov 2026. 

### Official description

A security vulnerability has been detected in TOTOLINK CA300-PoE 6.2c.884. Affected by this vulnerability is the function setWiFiWdsAddConfig of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ApCliKeyStr leads to buffer overflow. The attack may be initiated remotely. The exploit has been disclosed publicly and may be used.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-124059?


## How do I fix CVE-2026-124059?

No fix has been published for CVE-2026-124059 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-124059 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124059 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-124059 and fix it if it is affected.

What it is: CVE-2026-124059 is a critical vulnerability in TOTOLINK CA300-PoE, published on 7 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124059 exists.

Affected product: TOTOLINK CA300-PoE. 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-2026-124059/ (Markdown: https://insights.sbomify.com/CVE-2026-124059/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-124059
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124059
- OSV: https://osv.dev/vulnerability/CVE-2026-124059

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-124059/
Summaries are generated and may contain mistakes; the official description above is the record.