# CVE-2025-61939: Columbia Weather Systems MicroServer Improper Restriction of Communication Channel to Intended Endpoints

> An attacker with local network access and DNS control can hijack a reverse SSH connection to intercept data or bypass security controls.

- **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:** 7 Jan 2026
- **Updated:** 7 Jan 2026
- **Also known as:** GHSA-868w-86hc-x374

## What is CVE-2025-61939?

CVE-2025-61939 is a high-severity server-side request forgery vulnerability in Columbia Weather Systems MicroServer, published on 7 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An unused function in MicroServer can start a reverse SSH connection to a vendor registered domain, without mutual authentication. An attacker on the local network with admin access to the web server, and the ability to manipulate DNS responses, can redirect the SSH connection to an attacker controlled device.

Weakness: CWE-923 (Improper Restriction of Communication Channel to Intended Endpoints)

## Which versions are affected by CVE-2025-61939?

It affects 1 product.


Products: Columbiaweather Weather Microserver Firmware.

## How do I fix CVE-2025-61939?

No fix has been published for CVE-2025-61939 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-61939 being exploited?

There is no known exploitation of CVE-2025-61939 in the wild and no public exploit code.

## Other vulnerabilities in Columbia Weather Systems MicroServer

- [CVE-2018-18877](https://insights.sbomify.com/CVE-2018-18877/): Missing authorization in n/a (high 8.8)
- [CVE-2018-18879](https://insights.sbomify.com/CVE-2018-18879/): Command injection in n/a (high 8.8)
- [CVE-2025-66620](https://insights.sbomify.com/CVE-2025-66620/): Columbia Weather Systems MicroServer Command Shell in Externally Accessible Directory (high 8.6)
- [CVE-2018-18878](https://insights.sbomify.com/CVE-2018-18878/): Denial of service in n/a (high 7.5)
- [CVE-2018-18875](https://insights.sbomify.com/CVE-2018-18875/): Cross-site scripting in n/a (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-61939 and fix it if it is affected.

What it is: CVE-2025-61939 is a high-severity server-side request forgery vulnerability in Columbia Weather Systems MicroServer, published on 7 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-61939 in the wild and no public exploit code.

Affected product: Columbia Weather Systems MicroServer. 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-2025-61939/ (Markdown: https://insights.sbomify.com/CVE-2025-61939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-61939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-61939
- OSV: https://osv.dev/vulnerability/CVE-2025-61939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-61939/
Summaries are generated and may contain mistakes; the official description above is the record.