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TI-2026-20084 Aliases CVE-2026-24899GHSA-ffg9-j72f-j6xm

Fleet Windows MDM Azure AD JWT Authentication Bypass

Priority MEDIUM 44CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-290.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00381 32nd percentileScored 2026-11-07
Fix Fixed fleet (fleetdm): 4.82.0github.com/fleetdm/fleet/v4 (Go): 4.82.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
fleetdmfleetbefore 4.82.04.82.0Patch availableCNA
—github.com/fleetdm/fleet/v4 (Go)before 4.82.04.82.0Patch availableGHSA-ffg9-j72f-j6xm
  • fleet Vendorfleetdm Affected before 4.82.0 Fixed in 4.82.0 Patch available CNA
  • github.com/fleetdm/fleet/v4 (Go) Vendor— Affected before 4.82.0 Fixed in 4.82.0 Patch available GHSA-ffg9-j72f-j6xm

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*before 4.82.0Vulnerablefleetdm
  • cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* Versions before 4.82.0 Vulnerable ·fleetdm

Remediation

  • Fix · CNA fleet (fleetdm) Fixed in 4.82.0
  • Fix · GHSA-ffg9-j72f-j6xm github.com/fleetdm/fleet/v4 (Go) Fixed in 4.82.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-24899
  2. 2026-10-03 Alias added: GHSA-ffg9-j72f-j6xm

References

Advisory 2

Other 2

  • TI-2026-65639 Fleet before 4.87.0 Authentication Bypass via Device Identifiers CVSS 4.0CRITICAL 9.3
  • TI-2026-18942 Fleet has a JWT signature bypass vulnerability in Azure AD MDM enrollment CVSS 4.0CRITICAL 9.3
  • TI-2020-16097 SAML authentication vulnerability in Fleet CVSS 3.1CRITICAL 10.0
  • TI-2026-21066 Fleet server may terminate unexpectedly when handling certain gRPC requests CVSS 4.0HIGH 8.7
  • TI-2026-21065 Fleet's unbounded request body read allows remote Denial of Service CVSS 4.0HIGH 8.7
  • TI-2026-19339 Fleet has a rate limiting bypass via untrusted client IP headers CVSS 4.0MEDIUM 6.9
See all 31 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences