What is CVE-2026-103264?

CVE-2026-103264 is a critical-severity vulnerability in Fleetdm Fleet, classified under Improper Authentication. CVSS score: 9.1/10. Published 2026-10-01.

How severe is CVE-2026-103264?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Fleetdm Fleet

CVE-2026-103264

Fleet versions before 4.87.0 contain an authentication bypass vulnerability in the device API that accepts hostnames and hardware serials as authentication tokens in addition to device UUIDs. Unauthenticated attackers who know or guess these non-secret identifiers can authenticate as iOS/iPadOS hosts to read device data and trigger device-scoped actions including software installation and MDM migration.

Vulnerability class: Broken Authentication

Published 2026-10-01.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Fleetdm Fleet

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

github.com/fleetdm/fleet/security/advisories/GHSA-vrc8-2wcx-327f (vendor-advisory)
www.vulncheck.com/advisories/fleet-before-4.87.0-authentication-bypass-via-devi… (third-party-advisory)

Frequently asked questions

What is CVE-2026-103264?: CVE-2026-103264 is a critical-severity vulnerability in Fleetdm Fleet, classified under Improper Authentication. CVSS score: 9.1/10. Published 2026-10-01.
How severe is CVE-2026-103264?: Critical severity. CVSS v3 base score is 9.1 out of 10.