CVE-2026-41262 in Fleet
Summary
by MITRE • 08/26/2026
Fleet is an open-source device management platform built on osquery. In versions prior to 4.85.0, the global policy read endpoint (GET /api/latest/fleet/policies/{policy_id}) fails to verify team ownership of the requested policy, allowing an authenticated user with observer-level access on any single team to read the full details of policies belonging to any other team and bypass Fleet's team isolation model. The handler authorizes the request against an empty policy object whose TeamID is nil, which an authorization rule permits for any user holding a role on any team, and then fetches the policy by ID with no team filter and returns it without any post-fetch scope check. Because policy IDs are sequential integers, an attacker can enumerate them to read other teams' policy SQL queries, host pass and fail counts, and associated software-installer and script metadata, exposing security-monitoring strategies and compliance posture across team boundaries. This issue is fixed in version 4.85.0.
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified in Fleet versions prior to 4.85.0 represents a critical failure in access control logic within the device management platform's API layer, specifically affecting the global policy read endpoint located at GET /api/latest/fleet/policies/{policy_id}. As an open-source solution built on osquery, Fleet relies heavily on strict team isolation models to ensure that sensitive configuration data remains segregated between distinct organizational units or teams. The core technical flaw lies in the authorization handler for this specific API route, which fails to verify whether the requesting user possesses ownership or appropriate permissions relative to the target policy's assigned team. Instead of validating the relationship between the authenticated session and the resource being accessed, the system authorizes the request against an empty policy object where the TeamID field is nil. This design oversight allows any authenticated user who holds at least observer-level access on any single team within the Fleet instance to bypass isolation boundaries and retrieve data belonging to unrelated teams.
From a technical perspective, the exploitation mechanism involves manipulating the policy_id parameter in the API request. Because policy identifiers are implemented as sequential integers, an attacker can perform systematic enumeration by iterating through valid ID ranges. The backend logic fetches the requested policy record directly from the database using only this identifier without applying any additional team-scoped filters or post-fetch validation checks to ensure the retrieved resource belongs to a team for which the user has permissions. Consequently, even if the target policy is strictly confined to another team with no shared access rights, the API returns the full object payload. This behavior effectively nullifies the multi-tenancy security model intended by Fleet's architecture, creating a direct path for unauthorized data exfiltration across administrative boundaries.
The operational impact of this vulnerability is severe due to the sensitive nature of osquery policies and fleet configurations. These policy objects contain SQL queries used for host monitoring, compliance checks, and software installation scripts. By accessing these details, an attacker with low-level observer privileges can map out the security posture of other teams within the organization. This includes revealing specific detection rules for threats, understanding which endpoints are being monitored for compliance failures, and identifying installed software or executed scripts that may contain proprietary logic or internal infrastructure secrets. The exposure of host pass and fail counts further aids in reconnaissance by allowing attackers to identify vulnerable systems or misconfigurations across different teams without needing direct access to those environments. This level of information disclosure can facilitate more targeted attacks against the broader organization, as it provides a comprehensive view of defensive measures that would otherwise remain hidden behind team silos.
This vulnerability aligns with CWE-284 Improper Access Control and specifically reflects patterns associated with CWE-639 Authorization Bypass Through User-Controlled Key, where the identifier used to access a resource is not properly validated against authorization policies. In terms of offensive security frameworks, this behavior corresponds to MITRE ATT&CK technique T1078 Valid Accounts, as it leverages legitimate but low-privileged credentials to escalate information access privileges beyond their intended scope through logic flaws rather than credential compromise. The exploitation also touches upon T1592 Gather Victim Host Information by enumerating system configurations and security tools deployed across the network.
To mitigate this risk, organizations running Fleet versions prior to 4.85.0 must upgrade immediately to version 4.85.0 or later, where the authorization logic has been corrected to enforce strict team ownership verification before returning policy details. Until an upgrade is feasible, administrators should consider restricting API access through network-level controls such as firewalls or reverse proxy rules that limit exposure of the /api/latest/fleet/policies/ endpoint to only those users who require broad administrative privileges rather than general observer roles. Additionally, implementing strict rate limiting on this endpoint can help mitigate the efficiency of sequential ID enumeration attacks by introducing latency and detection opportunities for automated scanning tools attempting to harvest data across team boundaries.