Description

Fleet is an open-source device management platform built on osquery. In versions prior to 4.87.0, the target search endpoint (POST /api/latest/fleet/targets) returned unmasked team enroll secrets and full team configuration, including credential-bearing agent options, to low-privilege observer-class users. Other team-facing endpoints mask these fields for observers, but the target search endpoint did not apply the same sanitization, so an authenticated user with the Observer, Observer+, or Technician role, whether global or team-scoped, could retrieve the secrets and agent options by performing a target search against an observer-runnable query. With a leaked team enroll secret an attacker could enroll unauthorized hosts into the affected team, and if the team's agent options contained credentials such as AWS secret access keys or proxy passwords, those values were disclosed as well. This issue is fixed in version 4.87.0.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-26T19:16:50.643Z",
  "pubdate": "2026-08-26T19:16:50.643Z",
  "executiveSummary": "Fleet versions prior to 4.87.0 contain an information disclosure vulnerability within the target search API endpoint.\nThe vulnerability involves the improper access control and insufficient data sanitization of sensitive configuration parameters.\nSpecifically, the POST /api/latest/fleet/targets endpoint fails to mask team enroll secrets and team-specific agent options for users assigned low-privilege roles, such as Observer, Observer+, or Technician.\nSuccessful exploitation allows authenticated, low-privileged attackers to retrieve sensitive credentials, including AWS secret access keys and proxy passwords, alongside team enrollment secrets.\nThis disclosure facilitates unauthorized host enrollment into the victim's Fleet infrastructure and potential lateral movement or persistent access via leaked service credentials.\nThe risk is categorized as critical for organizations utilizing team-scoped configuration features, as it bypasses existing security controls that typically mask these fields for non-administrative roles.\nRemediation requires an immediate upgrade to Fleet version 4.87.0 or later to implement proper field sanitization logic on the affected endpoint.",
  "technicalDetails": "The root cause of this vulnerability is an inconsistency in the implementation of server-side data sanitization logic within the Fleet API infrastructure. While most team-facing endpoints are configured to redact sensitive fields—such as enrollment secrets and credential-bearing agent options—for users with Observer-class roles, the target search endpoint (POST /api/latest/fleet/targets) failed to apply these same security filters.\nThe vulnerability resides in the backend processing of the target search request. When an authenticated user with an Observer, Observer+, or Technician role submits a query to the /api/latest/fleet/targets endpoint, the application executes the search but returns a verbose JSON response that includes the full, unmasked team configuration object. This object contains metadata that is intended only for users with higher privilege levels (e.g., Maintainer or Admin).\nExploitation is straightforward for any authenticated user within the platform. The attack flow is as follows: 1) The attacker authenticates to the Fleet instance with an Observer or Technician role. 2) The attacker issues a POST request to /api/latest/fleet/targets with parameters consistent with an observer-runnable query. 3) The server fails to sanitize the response body before transmitting it to the client. 4) The attacker parses the JSON response to extract the clear-text 'enroll_secret' field and any additional credentials nested within the 'agent_options' configuration object.\nThe impact of this disclosure is twofold. First, the exposure of team enroll secrets allows an attacker to enroll unauthorized malicious hosts into the specific Fleet team, potentially facilitating the deployment of malicious osquery configurations. Second, the exposure of credentials within the agent options (such as AWS keys or proxy credentials) grants the attacker unauthorized access to external services or infrastructure integrated with the Fleet platform. This vulnerability affects all Fleet deployments prior to version 4.87.0, regardless of whether the user role is global or team-scoped, as long as the user possesses at least Observer-level access."
}