What is CVE-2026-26191?

CVE-2026-26191 is a critical-severity vulnerability in Fleetdm Fleet, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-05-14.

How severe is CVE-2026-26191?

Critical severity. CVSS v3 base score is 9.8 out of 10.

RCE in Fleetdm Fleet

CVE-2026-26191

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)…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.000 (10.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Fleetdm Fleet — versions < 4.81.1

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-26191?: CVE-2026-26191 is a critical-severity vulnerability in Fleetdm Fleet, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-05-14.
How severe is CVE-2026-26191?: Critical severity. CVSS v3 base score is 9.8 out of 10.