CVE-2026-26191
📛 CVE Title
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- GitHub_M
- CVSS severity
- MEDIUM
- CVSS score
- 6.0 / 10
- 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- Effective score
- 6.0 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-78 - Reserved
- 2026-02-11
- Published
- 2026-05-14 21:02 UTC
- Last updated
- 2026-05-15 16:15 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/26xxx/CVE-2026-26191.json
- Linked Threat
- CVE-2026-26191 — CVE-2026-26191
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-14 20:17:02 UTC
- NVD last modified
- 2026-05-18 14:05:02 UTC
- NVD CVSS v3.1
- 9.8 / 10 CRITICAL source: nvd@nist.gov
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 5.9 / 10
- EPSS score
- 0.0003 (probability of exploitation in next 30 days)
- EPSS percentile
- 10.15% vs all CVEs — higher = more likely to be exploited, as of 2026-05-25
NVD / KEV / EPSS data refreshed 2026-05-25 18:15 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-30376 - Assigner
- GitHub_M
- Published
- May 14, 2026, 7:02:12 PM
- Updated
- May 15, 2026, 2:15:18 PM
- EUVD base score (CVSS 4.0)
-
6.0 / 10
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 - EUVD-reported EPSS
- 0.0300
- Vendors
- fleetdm
- Products
-
Fleet (< 4.81.1)Fleet (< 4.81.1)
- Aliases
-
GHSA-9vcr-g537-3w5v
ENISA 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.
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| fleetdm | fleet |
< 4.81.1 (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*
Vendor references (2)
References embedded in the original CVE record by the assigning CNA.
- https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v x_refsource_CONFIRM
- https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 x_refsource_MISC
MITRE references (2) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 x_refsource_MISC
- https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v x_refsource_CONFIRM
Web references (3)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-26191 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-26191 tenable:www.cve.org
- https://www.first.org/epss/ tenable:www.first.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.1 security-advisories@github.com Release Notes
- https://github.com/fleetdm/fleet/security/advisories/GHSA-9vcr-g537-3w5v security-advisories@github.com Vendor Advisory
Remediations (15)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.qualys.com
Microsoft's February 2026 Patch Tuesday focuses on closing security gaps that attackers could exploit, reinforcing the importance of timely patching in enterprise environments. Here's a quick…
2026-05-23 20:53 UTC -
web:cyberpress.org
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .
2026-05-23 20:53 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-23 20:53 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 20:53 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's February 2026 Patch Tuesday with security updates for 58 flaws, including 6 actively exploited and three publicly disclosed zero-day vulnerabilities.
2026-05-23 20:53 UTC -
web:www.computerworld.com
Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...
2026-05-23 20:53 UTC -
web:www.crowdstrike.com
Microsoft's February 2026 Patch Tuesday addresses 59 CVEs , featuring six exploited vulnerabilities, three of which were publicly known, and five Critical vulnerabilities.
2026-05-23 20:53 UTC -
web:www.notebookcheck.net
Microsoft's February 2026 Windows 11 updates (KB5077181 and KB5075941) add security patches, bug fixes, and new Secure Boot rollout signals ahead of certificate expirations starting in June 2026 .
2026-05-23 20:53 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-23 20:53 UTC -
web:www.windowslatest.com
Windows 11 April 2026 update adds Narrator Copilot support, faster Settings, File Explorer fixes, and key security improvements.
2026-05-23 20:53 UTC -
web:cybersecuritynews.com
Microsoft released an out-of-band hotpatch update on March 13, 2026 , addressing serious security vulnerabilities in Windows 11 versions 24H2 and 25H2.
2026-05-26 02:56 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:56 UTC -
web:support.microsoft.com
The following summary outlines key issues addressed by this update. The bold text within the brackets indicates the item or area of the change. [Networking] Fixed: This update addresses a security issue in the Windows Routing and Remote Access Service (RRAS) management tool. If you connect to a malicious remote server, an attacker could disrupt the tool or run code on your device. For more ...
2026-05-26 02:56 UTC -
web:www.neowin.net
Microsoft has released Patch Tuesday updates for Windows 11 KB5077181, KB5075941 for February 2026 . Here's what's included.
2026-05-26 02:56 UTC -
web:www.windowslatest.com
Here is everything that is included in KB5077181: New features rolling out with the February 2026 Windows 11 update The February 2026 Patch Tuesday update introduces a solid set of new features ...
2026-05-26 02:56 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-26191.json.
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