{"id":"CVE-2026-101045","state":"PUBLISHED","title":"Fleet Homebrew Cask OS Command Injection via Metadata","description":"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.","publishedAt":"2026-09-27T17:02:34.472Z","updatedAt":"2026-09-30T17:20:13.569Z","severity":{"score":8.9,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","source":"VulnCheck"},"assigner":"VulnCheck","products":["fleetdm fleet"],"affected":[{"vendor":"fleetdm","product":"fleet","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2026-08-19","versionType":"custom"}]}],"references":["https://github.com/fleetdm/fleet/security/advisories/GHSA-fv3p-h7wv-2jgm","https://www.vulncheck.com/advisories/fleet-homebrew-cask-os-command-injection-via-metadata"],"weaknesses":["CWE-78"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/101xxx/CVE-2026-101045.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-101045","state":"PUBLISHED","datePublished":"2026-09-27T17:02:34.472Z","dateUpdated":"2026-09-30T17:20:13.569Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-27T15:48:49.472Z"},"containers":{"cna":{"title":"Fleet Homebrew Cask OS Command Injection via Metadata","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"fleetdm","product":"fleet","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2026-08-19","versionType":"custom"}]}],"references":[{"url":"https://github.com/fleetdm/fleet/security/advisories/GHSA-fv3p-h7wv-2jgm","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-fv3p-h7wv-2jgm)"},{"url":"https://www.vulncheck.com/advisories/fleet-homebrew-cask-os-command-injection-via-metadata","name":"VulnCheck Advisory: Fleet Homebrew Cask OS Command Injection via Metadata","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","baseScore":8.9,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":8,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-78","lang":"en","description":"Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-30T17:20:13.569Z"},"datePublic":"2026-09-11T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:fleetdm:fleet:-:*:*:*:*:*:*:*"}]}]}],"credits":[{"lang":"en","value":"arpitjain099","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T14:11:11.667554Z","id":"CVE-2026-101045","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T14:11:33.214Z"}}]}}}