CVE-2026-26191: Fleet is open source device management software

Q: How do I fix CVE-2026-26191?

fleet: upgrade to 4.81.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-26191 being exploited?

CVE-2026-26191 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-26191 affect?

CVE-2026-26191 affects fleet. Severity is critical (CVSS 9.8). 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)

Q: How urgent is CVE-2026-26191?

Priority 53/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-26191 is a critical-severity flaw (CVSS 9.8) affecting fleet. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 45%)
CISA exploited list	No
Weakness	CWE-78
Published	2026-05-14
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: fleetdm

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-14 20:17 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

fleetdm fleet UPGRADE

Affected: < 4.81.0

Fixed in: 4.81.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fleet || rpm -q fleet || fleet --version

2. UPGRADE to 4.81.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fleet

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fleet

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-26191?

fleet: upgrade to 4.81.0. Exact commands for each OS are on this page.

Is CVE-2026-26191 being exploited?

CVE-2026-26191 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-26191 affect?

CVE-2026-26191 affects fleet. Severity is critical (CVSS 9.8). 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)

How urgent is CVE-2026-26191?

Priority 53/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Windows vulnerabilities · macOS vulnerabilities

Related CVEs

CVE-2026-24899 HIGH 7.5 UPGRADE Fleet is open source device management software
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CVE-2026-23998 HIGH 7.5 UPGRADE Fleet is open source device management software
CVE-2026-24000 MEDIUM 5.3 UPGRADE Fleet is open source device management software
CVE-2026-26062 MEDIUM 6.5 UPGRADE Fleet is open source device management software

References

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