Fleet Windows MDM Azure AD JWT Authentication Bypass_CVE-2026-24899

8.2 / 10

HIGH

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Description

Fleet is open source device management software. Prior to version 4.82.0, a vulnerability in Fleet's Windows MDM enrollment flow allows authentication tokens from any Azure AD tenant to be accepted. Because Fleet validates JWT signatures using Microsoft's multi-tenant JWKS endpoint but does not enforce the `aud` (audience) or `iss` (issuer) claims, any Microsoft-signed Azure AD access token containing the expected scopes can be used to authenticate to Fleet's MDM endpoints. If Windows MDM is enabled, an attacker with access to any Azure AD tenant can obtain a valid Microsoft-signed token and use it to enroll unauthorized devices and interact with Fleet's MDM management APIs. During device management, Fleet may expose sensitive enrollment secrets embedded in MDM command payloads, enabling further unauthorized access. Version 4.82.0 contains a patch. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM.

Basic Information

ID CVE-2026-24899

Source GitHub_M

Published May 14, 2026 at 18:58

Affected Product

Vendor fleetdm

Product fleet

Version < 4.82.0

Affected Versions fleetdm fleet < 4.82.0

CWE Classification

CWE-290

References

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    "published": "2026-05-14T18:58:26.550Z",
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