CVE-2026-48786: Fleet Observer-class Users Can View Team Vulnerability

MODERATE
Advisory Identifier: GHSA-88p2-jj8w-j8qg
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CVSS 6.5
CWE-200
Published
Advisory Summary

CVE-2026-48786 is a MODERATE (CVSS 6.5) observer-class users can view team vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Fleet libraries in the Go ecosystem. The issue involves observer-class users can view team enroll secrets and credential-bearing configuration via target search endpoint. Remediation is available by upgrading affected packages to version 4.87.0.

CVE-2026-48786 at a Glance

CVE Identifier CVE-2026-48786
GHSA Identifier GHSA-88p2-jj8w-j8qg
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Fleet
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-48786

To remediate this vulnerability, upgrade all affected Fleet dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/fleetdm/fleet/v4 fixed: 4.87.0 
Upgrade github.com/fleetdm/fleet/v4 to 4.87.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/fleetdm/fleet/v4

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-48786, inspect your project dependencies for Fleet:

inspect dependencies for github.com/fleetdm/fleet/v4

Analyze the terminal output to locate any version of Fleet in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.87.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. In Fleet, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The target search endpoint (`POST /api/latest/fleet/targets`) returned team enroll secrets and full team configuration, including credential-bearing agent options, to observer-class users. Other team-facing endpoints mask these fields for observers; the target search endpoint did not apply the same sanitization. ### Impact An authenticated user with Observer, Observer+, or Technician role (global or team-scoped) could retrieve unmasked team enroll secrets and team 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. If the team's agent options contained credentials such as AWS secret access keys or proxy passwords, those values were also exposed. ### Patches - v4.87.0 ### Workarounds If an immediate upgrade is not possible, administrators should: - Rotate team enroll secrets for any team that may have been exposed - Rotate any credentials stored in team agent options (AWS keys, proxy passwords, session tokens) - Restrict Observer and Technician roles to fully trusted users until the patch is applied ### Credits Fleet thanks @fuzzztf for responsibly reporting this issue. ### For more information If there are any questions or comments about this advisory: Send an email to [security@fleetdm.com](mailto:security@fleetdm.com) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)

CVE-2026-48786 Affected Fleet Versions

1 component(s)
Fixed Versions:
4.87.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/fleetdm/fleet/v4
golang/github.com/fleetdm/fleet/v4
Go
< 4.87.0
4.87.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/fleetdm/fleet/security/advisories/GHSA-88p2-jj8w-j8qg
Fleet Source Repository REPOSITORY
https://github.com/fleetdm/fleet
Fleet Release RELEASE
https://github.com/fleetdm/fleet/releases/tag/fleet-v4.87.0

Frequently Asked Questions

What is CVE-2026-48786?
CVE-2026-48786 is a security vulnerability in Fleet involving Observer-class users can view team enroll secrets and credential-bearing configuration via target search endpoint under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Fleet versions are affected?
Affected versions include releases prior to 4.87.0 across affected packages: github.com/fleetdm/fleet/v4.
What version fixes CVE-2026-48786?
Upgrading to 4.87.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/fleetdm/fleet/v4 affected?
Yes, github.com/fleetdm/fleet/v4 is affected in releases prior to 4.87.0. Upgrade your dependency to 4.87.0 or later.
What is the CVSS score of CVE-2026-48786?
CVE-2026-48786 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-48786?
CVE-2026-48786 is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.).
How can I check Go dependencies for CVE-2026-48786?
Run the dependency tree command: 'inspect dependencies for github.com/fleetdm/fleet/v4'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-88p2-jj8w-j8qg",
  "modified" : "2026-08-12T15:18:13Z",
  "published" : "2026-08-12T15:18:13Z",
  "aliases" : [ "CVE-2026-48786" ],
  "summary" : "Fleet: Observer-class users can view team enroll secrets and credential-bearing configuration via target search endpoint",
  "details" : "### Summary\n\nThe target search endpoint (`POST /api/latest/fleet/targets`) returned team enroll secrets and full team configuration, including credential-bearing agent options, to observer-class users. Other team-facing endpoints mask these fields for observers; the target search endpoint did not apply the same sanitization.\n\n### Impact\n\nAn authenticated user with Observer, Observer+, or Technician role (global or team-scoped) could retrieve unmasked team enroll secrets and team agent options by performing a target search against an observer-runnable query.\n\nWith a leaked team enroll secret, an attacker could enroll unauthorized hosts into the affected team. If the team's agent options contained credentials such as AWS secret access keys or proxy passwords, those values were also exposed.\n\n### Patches\n\n- v4.87.0\n\n### Workarounds\n\nIf an immediate upgrade is not possible, administrators should:\n\n- Rotate team enroll secrets for any team that may have been exposed\n- Rotate any credentials stored in team agent options (AWS keys, proxy passwords, session tokens)\n- Restrict Observer and Technician roles to fully trusted users until the patch is applied\n\n### Credits\n\nFleet thanks @fuzzztf for responsibly reporting this issue.\n\n### For more information\n\nIf there are any questions or comments about this advisory:\n\nSend an email to [security@fleetdm.com](mailto:security@fleetdm.com)\nJoin #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/fleetdm/fleet/v4"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.87.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/fleetdm/fleet/security/advisories/GHSA-88p2-jj8w-j8qg"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/fleetdm/fleet"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/fleetdm/fleet/releases/tag/fleet-v4.87.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-12T15:18:13Z",
    "nvd_published_at" : null
  }
}