---
id: CVE-2026-101045
title: >-
  Fleet-maintained app install and uninstall scripts for macOS are generated
  from Homebrew cask metadata
summary: >-
  Fleet-maintained app install and uninstall scripts for macOS are generated
  from Homebrew cask metadata. In manifests generated before 2026-08-19, the
  script generator escaped this metadata at some interpolation sites but not all
  of them,…
severity: high
cvss: 8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-78
vendor: fleetdm
product: fleet
affected:
  - fleet
published: '2026-09-27'
updated: '2026-09-27'
sourceUpdated: '2026-09-27T18:16:30.897'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101045'
references:
  - url: 'https://github.com/fleetdm/fleet/security/advisories/GHSA-fv3p-h7wv-2jgm'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/fleet-homebrew-cask-os-command-injection-via-metadata
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-27T17:56:02.211Z'
---

## Overview

Fleet-maintained app install and uninstall scripts for macOS are generated from Homebrew cask metadata. In manifests generated before 2026-08-19, the script generator escaped this metadata at some interpolation sites but not all of them, so cask metadata containing shell metacharacters (for example $(...) command substitution) could be carried into scripts that execute as root on managed macOS hosts. An attacker who could land crafted metadata in an upstream Homebrew cask — without needing any Fleet credentials — could achieve arbitrary command execution as root on managed macOS hosts that install or uninstall the affected Fleet-maintained app; exploitation required the crafted metadata to pass both upstream Homebrew cask review and Fleet's review of the automated ingestion pull request. The fix (fleetdm/fleet#51324) landed in Fleet's ingestion pipeline on 2026-08-19 so that all manifests generated on or after that date escape cask metadata at every interpolation site; because manifests are generated centrally and distributed as pre-built content, remediation applied to all deployments with no customer action, and the code fix is included in Fleet v4.92.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.