# CVE-2021-47726: NuCom 11N Wireless Router 5.07.90 Privilege Escalation via Configuration Backup

> Attackers can escalate privileges and read admin credentials by sending a crafted HTTP request to the configuration backup endpoint on NuCom routers.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **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 Dec 2025
- **Updated:** 2 Jan 2026
- **Also known as:** GHSA-f57r-vv46-fp7w

## What is CVE-2021-47726?

CVE-2021-47726 is a high-severity vulnerability in NuCom 11N Wireless Router, published on 31 Dec 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

NuCom 11N Wireless Router 5.07.90 contains a privilege escalation vulnerability that allows non-privileged users to access administrative credentials through the configuration backup endpoint. Attackers can send a crafted HTTP GET request to the backup configuration page with a specific cookie to retrieve and decode the admin password in Base64 format.

Weakness: CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2021-47726?


## How do I fix CVE-2021-47726?

No fix has been published for CVE-2021-47726 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47726 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47726 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47726 and fix it if it is affected.

What it is: CVE-2021-47726 is a high-severity vulnerability in NuCom 11N Wireless Router, published on 31 Dec 2025. 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-2021-47726 exists.

Affected product: NuCom 11N Wireless Router. 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-2021-47726/ (Markdown: https://insights.sbomify.com/CVE-2021-47726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47726
- OSV: https://osv.dev/vulnerability/CVE-2021-47726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47726/
Summaries are generated and may contain mistakes; the official description above is the record.