# CVE-2026-104805: Mitel MiVoice Office 400 Backup Restoration Arbitrary File Write Leading to Root Code Execution

> An attacker with backup repository access can upload a malicious archive to achieve root code execution on the Mitel MiVoice Office 400 system.

- **Severity:** High 8.5 (`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/AU:Y/R:U/V:D/RE:M/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-vh23-h9qx-6q3f

## What is CVE-2026-104805?

CVE-2026-104805 is a high-severity path traversal vulnerability in Mitel MiVoice Office 400, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

DigitalCanion has discovered a vulnerability in the backup restoration functionality that allows an attacker with access to the configured backup repository to introduce arbitrary files into the system during restoration.

The specific flaw exists within the backup restoration mechanism, which fails to properly validate the paths, file types, integrity, and authenticity of files contained within a restored TGZ archive. The application does not perform file-signature verification before extracting the archive, allowing a specially crafted backup to contain attacker-controlled files.

An attacker with access to the backup SFTP or other configured repository can therefore provide a malicious TGZ archive that, when restored by the system, may place arbitrary files on the underlying Linux system. Depending on the location and permissions of the extracted files, this behavior can potentially be leveraged to achieve arbitrary code execution with root privileges and compromise the underlying virtual machine.

The absence of enforced backup passwords further reduces the protection provided by the backup mechanism and may facilitate unauthorized access to the repository.

Weakness: CWE-494 (Download of Code Without Integrity Check), CWE-434 (Unrestricted Upload of File with Dangerous Type), CWE-345 (Insufficient Verification of Data Authenticity), CWE-73 (External Control of File Name or Path), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-104805?


## How do I fix CVE-2026-104805?

No fix has been published for CVE-2026-104805 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104805 being exploited?

There is no known exploitation of CVE-2026-104805 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104805 and fix it if it is affected.

What it is: CVE-2026-104805 is a high-severity path traversal vulnerability in Mitel MiVoice Office 400, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-104805 in the wild and no public exploit code.

Affected product: Mitel MiVoice Office 400. 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-2026-104805/ (Markdown: https://insights.sbomify.com/CVE-2026-104805/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104805
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104805
- OSV: https://osv.dev/vulnerability/CVE-2026-104805

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-104805/
Summaries are generated and may contain mistakes; the official description above is the record.