CVE-2026-26191: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in fleetdm fleet
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.
AI Analysis
Technical Summary
Fleet is an open source device management tool. Before version 4.81.0, when software packages (.pkg, .deb, .rpm, .exe, .msi) are uploaded, metadata is extracted and used to create uninstall scripts. The metadata is not sanitized properly, allowing specially crafted metadata to inject OS commands that execute with elevated privileges (root on macOS/Linux, SYSTEM on Windows) during uninstall. This vulnerability is identified as CVE-2026-26191 and classified under CWE-78 (OS Command Injection). The issue is fixed in version 4.81.0.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary commands with root or SYSTEM privileges on managed endpoints during the uninstall process of a software package. This can lead to full system compromise on affected devices. The vulnerability affects Fleet versions prior to 4.81.0. There are no known exploits in the wild as of the published date.
Mitigation Recommendations
Upgrade Fleet to version 4.81.0 or later, which contains a patch for this vulnerability. If immediate upgrade is not feasible, avoid uploading software packages from untrusted or unverified sources. Additionally, manually inspect and edit the auto-generated uninstall scripts before deploying them to managed endpoints to ensure no malicious commands are present.
CVE-2026-26191: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in fleetdm fleet
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.
CVSS v4.0
Score 6.0medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Fleet is an open source device management tool. Before version 4.81.0, when software packages (.pkg, .deb, .rpm, .exe, .msi) are uploaded, metadata is extracted and used to create uninstall scripts. The metadata is not sanitized properly, allowing specially crafted metadata to inject OS commands that execute with elevated privileges (root on macOS/Linux, SYSTEM on Windows) during uninstall. This vulnerability is identified as CVE-2026-26191 and classified under CWE-78 (OS Command Injection). The issue is fixed in version 4.81.0.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary commands with root or SYSTEM privileges on managed endpoints during the uninstall process of a software package. This can lead to full system compromise on affected devices. The vulnerability affects Fleet versions prior to 4.81.0. There are no known exploits in the wild as of the published date.
Mitigation Recommendations
Upgrade Fleet to version 4.81.0 or later, which contains a patch for this vulnerability. If immediate upgrade is not feasible, avoid uploading software packages from untrusted or unverified sources. Additionally, manually inspect and edit the auto-generated uninstall scripts before deploying them to managed endpoints to ensure no malicious commands are present.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-02-11T19:56:24.812Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a062489ec166c07b00b4bc8
Added to database: 05/14/2026, 19:37:45 UTC
Last enriched: 05/14/2026, 19:53:26 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 82
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