CVE-2026-103264 PUBLISHED

Fleet before 4.87.0 Authentication Bypass via Device Identifiers

Assigner: VulnCheck
Reserved: 30.09.2026 Published: 01.10.2026 Updated: 01.10.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 9.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS Score: 9.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	fleetdm
Product	fleet
Versions	Default: unaffected affected from 0 to 4.87.0 (excl.) Version 4.87.0 is unaffected

References

Problem Types

Improper Authentication CWE