CVE-2026-46370 — github.com/fleetdm/fleet/v4
Exposure of Sensitive Information to an Unauthorized ActorSummary
A vulnerability in Fleet's labels host-listing endpoint allowed authenticated users with the lowest-privilege Observer role to extract host enrollment secrets (node_key, orbit_node_key) through a cursor-based binary search oracle. The endpoint accepted a user-supplied order_key parameter that was not validated against a column allowlist, permitting sort order to be driven by sensitive columns in a joined table.
Impact
The GET /api/v1/fleet/labels/{id}/hosts endpoint constructs its query using a deprecated helper that did not restrict which columns could appear in the ORDER BY clause. An attacker with Global Observer or Team Observer credentials could supply a sensitive column name (for example, h.node_key) as order_key and combine it with the cursor-based after parameter to binary-search the values of those columns one character at a time. The targeted values never appeared in the response body, but the presence or absence of results revealed each character.
The node_key and orbit_node_key values are the long-lived shared secrets used by osquery and Orbit agents to authenticate to the Fleet server. An attacker who extracted these keys could:
- Impersonate enrolled hosts to Fleet's osquery and Orbit endpoints
- Submit fabricated query results and host inventory data
- Retrieve pending scripts and MDM commands queued for the host
- Poison compliance and policy results across the Fleet deployment
Exploitation required authenticated Observer access. Fleet deployments that restrict Observer roles to fully trusted users were at lower practical risk, but the secrets exposed are high-value and long-lived.
Patches
- v4.85.0
Workarounds
If an immediate upgrade is not possible, administrators should:
- Restrict the Observer role to fully trusted users until the patch is applied
- Rotate
node_keyandorbit_node_keyfor any host suspected of exposure by re-enrolling the affected hosts
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 the Security Team at Palantir Technologies for responsibly reporting this issue.
| Software | From | Fixed in |
|---|---|---|
github.com/fleetdm/fleet/v4
|
- | 4.84.2 |
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Frequently Asked Questions
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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