# CVE-2026-27806: Fleet Affected by Local Privilege Escalation via Tcl Command Injection in Orbit

> Local attackers can escalate to root privileges by injecting Tcl commands via a crafted password during FileVault key rotation in the Fleet Orbit agent.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Apr 2026
- **Updated:** 9 Apr 2026
- **Also known as:** GHSA-rphv-h674-5hp2, GO-2026-5634

## What is CVE-2026-27806?

CVE-2026-27806 is a high-severity command injection vulnerability in fleetdm fleet, published on 8 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Fleet is open source device management software. Prior to 4.81.1, the Orbit agent's FileVault disk encryption key rotation flow on collects a local user's password via a GUI dialog and interpolates it directly into a Tcl/expect script executed via exec.Command("expect", "-c", script). Because the password is inserted into Tcl brace-quoted send {%s}, a password containing } terminates the literal and injects arbitrary Tcl commands. Since Orbit runs as root, this allows a local unprivileged user to escalate to root privileges. This vulnerability is fixed in 4.81.1.

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

## Which versions are affected by CVE-2026-27806?

3 open source packages ship an affected version, including github.com/fleetdm/fleet/v4. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/fleetdm/fleet/v4` | Go | All versions | 4.81.1 |
| `github.com/fleetdm/fleet/v4` | Go | All versions | 4.81.1 |
| `github.com/fleetdm/fleet/v4` | Go | All versions | 4.81.1 |

Products: Fleetdm Fleet.

## How do I fix CVE-2026-27806?

Upgrade github.com/fleetdm/fleet/v4 to 4.81.1 or later.

## Is CVE-2026-27806 being exploited?

There is no known exploitation of CVE-2026-27806 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-2026-27806 and fix it if it is affected.

What it is: CVE-2026-27806 is a high-severity command injection vulnerability in fleetdm fleet, published on 8 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-27806 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/fleetdm/fleet/v4 (Go): affected all versions; fixed in 4.81.1
- github.com/fleetdm/fleet/v4 (Go): affected all versions; fixed in 4.81.1
- github.com/fleetdm/fleet/v4 (Go): affected all versions; fixed in 4.81.1

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-2026-27806/ (Markdown: https://insights.sbomify.com/CVE-2026-27806/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27806
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27806
- OSV: https://osv.dev/vulnerability/CVE-2026-27806

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27806/
Summaries are generated and may contain mistakes; the official description above is the record.