CVE-2026-26191
Fleet vulnerable to OS command injection in software packages
Description
Fleet is open source device management software. Prior to version 4.81.0, 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. 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. Version 4.81.0 contains a patch. 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.
INFO
Published Date :
May 14, 2026, 8:17 p.m.
Last Modified :
Oct. 26, 2026, 2:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Upgrade Fleet software to version 4.81.0 or newer.
- Avoid uploading software from untrusted sources.
- Inspect and edit uninstall scripts manually.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-26191.
| URL | Resource |
|---|---|
| https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 | Release Notes |
| https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-26191 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-26191
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-26191 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-26191 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: fleet de fleetdm, Description: Fleet es un software de gestión de dispositivos de código abierto. Antes de la versión 4.81.0, una vulnerabilidad en la cadena de instalación de software de Fleet podría permitir que un paquete de software manipulado ejecute comandos arbitrarios como root (macOS/Linux) o SYSTEM (Windows) en los puntos finales gestionados cuando se activa una desinstalación. Cuando un paquete de software (.pkg, .deb, .rpm, .exe o .msi) se carga en Fleet, se extraen metadatos del binario del paquete y se utilizan para generar scripts de desinstalación. En las versiones afectadas, estos metadatos no se sanean correctamente antes de ser incluidos en los scripts generados. Un paquete especialmente manipulado que contenga valores maliciosos en sus campos de metadatos podría resultar en la ejecución de comandos no deseados cuando el script de desinstalación se ejecuta en los puntos finales gestionados. La versión 4.81.0 contiene un parche. Si una actualización inmediata no es posible, los administradores deben evitar cargar paquetes de software obtenidos de fuentes no confiables o no verificadas. Además, los administradores pueden inspeccionar y editar manualmente los scripts de desinstalación autogenerados antes de la implementación. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'fleetdm', 'product': 'fleet', 'versions': [{'status': 'affected', 'version': '< 4.81.1'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-26191', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-05-15T14:15:05.427993Z'} -
Initial Analysis by [email protected]
May. 18, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* versions up to (excluding) 4.81.0 Added Reference Type GitHub, Inc.: https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v Types: Vendor Advisory -
New CVE Received by [email protected]
May. 14, 2026
Action Type Old Value New Value Added Description Fleet is open source device management software. Prior to version 4.81.0, 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. 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. Version 4.81.0 contains a patch. 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-78 Added Reference https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 Added Reference https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v