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.
- 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
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
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 | 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 include Fleetdm Fleet.
How do I fix CVE-2026-27806?
Upgrade github.com/fleetdm/fleet/v4 to 4.81.1 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
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 SAML authentication vulnerability in Fleet
- CVE-2026-103264 Fleet before 4.87.0 Authentication Bypass via Device Identifiers
- CVE-2026-23518 Fleet has a JWT signature bypass vulnerability in Azure AD MDM enrollment
- CVE-2026-26062 Fleet server may terminate unexpectedly when handling certain gRPC requests
- CVE-2026-26061 Fleet's unbounded request body read allows remote Denial of Service
Sources
Also known as GHSA-rphv-h674-5hp2, GO-2026-5634.