GitHub Advisoryadvisory · Go

GHSA-9vcr-g537-3w5v Fleet vulnerable to OS command injection in software packages

MEDIUM Published 2026-05-14 Modified 2026-05-15 Official page ↗
Aliases
CVE-2026-26191
Ecosystem
Go
Packages
github.com/fleetdm/fleet/v4
Severity
Moderate
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-78
Reviewed
2026-05-14

Affected packages

• Go github.com/fleetdm/fleet/v4: < 4.81.1 → fixed in 4.81.1

Description

Summary A vulnerability in Fleet's software installer pipeline could allow a crafted software package to execute arbitrary commands as root (macOS/Linux) or SYSTEM (Windows) on managed endpoints when an uninstall is triggered. Impact When a software package (.pkg, .deb, .rpm, .exe, or .msi) is uploaded to Fleet, metadata is extracted from the package binary and used to generate uninstall scripts. In affected versions, this metadata is not properly sanitized before being included in the generated scripts. A specially crafted package containing malicious values in its metadata fields could result in unintended command execution when the uninstall script runs on managed endpoints. Workarounds If an immediate upgrade is not possible, administrators should avoid uploading software packages obtained from untrusted or unverified sources. Additionally, administrators can manually inspect and edit auto-generated uninstall scripts before deployment. For more information If you have any questions or comments about this advisory: Email us at [[email protected]](mailto:[email protected]) Join #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw) Credits We thank @secfox-ai for responsibly reporting this issue.

Related

Alias · CVE (1)

  • CVE-2026-26191 Fleet is open source device management software. vulnerability

Weakness · CWE (1)

  • CWE-78 Improper Neutralization of Special Elements used in an OS Command weakness

References