CVE-2026-29180 — v4
CVE-2026-29180 is a CWE-862 vulnerability in github.com/fleetdm/fleet/v4. A fix is available for github.com/fleetdm/fleet/v4 — see the affected versions and patch details below.
Fleet's team maintainer can transfer hosts from any team via missing source team authorization
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-29180.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/fleetdm/fleet/v4Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
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.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/fleetdm/fleet/v4 | all versions | 4.81.1go get github.com/fleetdm/fleet/v4@v4.81.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fleetdm/fleet/v4, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/fleetdm/fleet/v4 to 4.81.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29180 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-29180 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-29180. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-29180 in your dependencies?
O3 Security finds CVE-2026-29180 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.