CVE-2026-103264: Fleet before 4.87.0 Authentication Bypass via Device Identifiers

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-01 · updated 2026-10-08
Weakness: CWE-287

Description

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.

Affected products

fleetdm fleet: before 4.87.0 — fixed in 4.87.0

How to fix

Upgrade to a fixed version: fleetdm fleet 4.87.0. Check the vendor advisory for mitigations.

References

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