Summary
A Fleet team maintainer can transfer hosts from any team via missing source team authorization
A broken access control vulnerability in Fleet's host transfer API allows a team maintainer to transfer hosts from any team into their own team, bypassing team isolation boundaries. Once transferred, the attacker gains full control over the stolen hosts, including the ability to execute scripts with root privileges.
Workarounds
There is no workaround for this issue short of upgrading to a patched version. Organizations concerned about exploitation should audit host transfer activity in their Fleet logs for any unexpected team reassignments.
For more information
If there are any questions or comments about this advisory:
Email Fleet at [email protected]
Join #fleet in osquery Slack
Credits
Fleet thanks @secfox-ai for responsibly reporting this issue.
Impact
The host transfer endpoints verify that the caller has write permission to the destination team but do not check whether the caller has any permission over the source team of the hosts being transferred.
Once hosts are transferred, the attacker's team MDM configuration is automatically applied to the stolen devices, and the attacker can execute scripts on them with root privileges. In multi-tenant Fleet deployments where teams represent business units, departments, or customers, this breaks all team isolation guarantees. A bulk transfer variant allows stealing all matching hosts fleet-wide in a single request.
Exploitation requires authentication as a team maintainer or team admin.
The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-29180? CVE-2026-29180 is a medium-severity missing authorization vulnerability in github.com/fleetdm/fleet/v4 (go), affecting versions < 4.81.1. It is fixed in 4.81.1. The application does not perform an authorization check before performing a sensitive operation.
- Which versions of github.com/fleetdm/fleet/v4 are affected by CVE-2026-29180? github.com/fleetdm/fleet/v4 (go) versions < 4.81.1 is affected.
- Is there a fix for CVE-2026-29180? Yes. CVE-2026-29180 is fixed in 4.81.1. Upgrade to this version or later.
- Is CVE-2026-29180 exploitable, and should I be worried? Whether CVE-2026-29180 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-29180 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-29180? Upgrade
github.com/fleetdm/fleet/v4to 4.81.1 or later.