# CVE-2025-41766: Stack buffer overflow on parsing web request

> A remote attacker can achieve full device compromise via a stack buffer overflow in the web request parser.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 9 Mar 2026
- **Updated:** 9 Mar 2026
- **Also known as:** GHSA-fp48-r694-65jv

## What is CVE-2025-41766?

CVE-2025-41766 is a high-severity memory corruption vulnerability in MBS UBR-01 Mk II, published on 9 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A low-privileged remote attacker can trigger a stack-based buffer overflow via a crafted HTTP POST request using the ubr-network method resulting in full device compromise.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-41766?

It affects 1 product.


Products: Mbs-Solutions Universal Bacnet Router Firmware.

## How do I fix CVE-2025-41766?

No fix has been published for CVE-2025-41766 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-41766 being exploited?

There is no known exploitation of CVE-2025-41766 in the wild and no public exploit code.

## Other vulnerabilities in MBS UBR-01 Mk II

- [CVE-2025-41764](https://insights.sbomify.com/CVE-2025-41764/): Unchecked role in wwwupdate.cgi (critical 9.1)
- [CVE-2025-41765](https://insights.sbomify.com/CVE-2025-41765/): Unchecked role in wwwupload.cgi (critical 9.1)
- [CVE-2025-41757](https://insights.sbomify.com/CVE-2025-41757/): Arbitrary Write with ubr-restore (high 8.8)
- [CVE-2025-41758](https://insights.sbomify.com/CVE-2025-41758/): Arbitrary Write with wwwupload.cgi (high 8.8)
- [CVE-2025-41756](https://insights.sbomify.com/CVE-2025-41756/): Arbitrary Write with ubr-editfile (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-41766 and fix it if it is affected.

What it is: CVE-2025-41766 is a high-severity memory corruption vulnerability in MBS UBR-01 Mk II, published on 9 Mar 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-2025-41766 in the wild and no public exploit code.

Affected product: MBS UBR-01 Mk II. 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-2025-41766/ (Markdown: https://insights.sbomify.com/CVE-2025-41766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-41766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-41766
- OSV: https://osv.dev/vulnerability/CVE-2025-41766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-41766/
Summaries are generated and may contain mistakes; the official description above is the record.