# CVE-2026-34387: Fleet vulnerable to OS command injection via crafted software package metadata in uninstall scripts

> Attackers can execute arbitrary code as root or SYSTEM on managed hosts via crafted software package metadata in uninstall scripts.

- **Severity:** Medium 5.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Mar 2026
- **Updated:** 27 Mar 2026
- **Also known as:** GHSA-7rhw-5mpv-gp4h

## What is CVE-2026-34387?

CVE-2026-34387 is a medium-severity command injection vulnerability in fleetdm fleet, published on 27 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Fleet is open source device management software. Prior to 4.81.1, a command injection vulnerability in Fleet's software installer pipeline allows an attacker to achieve arbitrary code execution as root (macOS/Linux) or SYSTEM (Windows) on managed hosts when an uninstall is triggered for a crafted software package. Version 4.81.1 patches the issue.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-34387?

It affects 1 product.


Products: Fleetdm Fleet.

## How do I fix CVE-2026-34387?

No fix has been published for CVE-2026-34387 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34387 being exploited?

There is no known exploitation of CVE-2026-34387 in the wild and no public exploit code.

## Other vulnerabilities in fleetdm fleet

- [CVE-2020-26276](https://insights.sbomify.com/CVE-2020-26276/): SAML authentication vulnerability in Fleet (critical 10.0)
- [CVE-2026-103264](https://insights.sbomify.com/CVE-2026-103264/): Fleet before 4.87.0 Authentication Bypass via Device Identifiers (critical 9.3)
- [CVE-2026-23518](https://insights.sbomify.com/CVE-2026-23518/): Fleet has a JWT signature bypass vulnerability in Azure AD MDM enrollment (critical 9.3)
- [CVE-2026-26062](https://insights.sbomify.com/CVE-2026-26062/): Fleet server may terminate unexpectedly when handling certain gRPC requests (high 8.7)
- [CVE-2026-26061](https://insights.sbomify.com/CVE-2026-26061/): Fleet's unbounded request body read allows remote Denial of Service (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34387 and fix it if it is affected.

What it is: CVE-2026-34387 is a medium-severity command injection vulnerability in fleetdm fleet, published on 27 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-34387 in the wild and no public exploit code.

Affected product: fleetdm fleet. 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-2026-34387/ (Markdown: https://insights.sbomify.com/CVE-2026-34387/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34387
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34387
- OSV: https://osv.dev/vulnerability/CVE-2026-34387

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34387/
Summaries are generated and may contain mistakes; the official description above is the record.