Read the docs
TI-2026-26675 Aliases CVE-2026-34389GHSA-4f9r-x588-pp2h

Fleet's user account creation via invite does not enforce invited email address

Priority LOW 28CWE-287Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.

Summary

Fleet is open source device management software. Prior to 4.81.0, Fleet contained an issue in the user invitation flow where the email address provided during invite acceptance was not validated against the email address associated with the invite. An attacker who obtained a valid invite token could create an account under an arbitrary email address while inheriting the role granted by the invite, including global admin. Version 4.81.0 patches the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00192 8th percentileScored 2026-11-07
Fix Fixed fleet (fleetdm): 4.81.0github.com/fleetdm/fleet/v4 (Go): 4.81.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

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 4.81.04.81.0Patch availableCNA
—github.com/fleetdm/fleet/v4 (Go)before 4.81.04.81.0Patch availableGHSA-4f9r-x588-pp2h
  • fleet Vendorfleetdm Affected before 4.81.0 Fixed in 4.81.0 Patch available CNA
  • github.com/fleetdm/fleet/v4 (Go) Vendor— Affected before 4.81.0 Fixed in 4.81.0 Patch available GHSA-4f9r-x588-pp2h

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*before 4.81.1Vulnerablefleetdm
  • cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* Versions before 4.81.1 Vulnerable ·fleetdm

Remediation

  • Fix · CNA fleet (fleetdm) Fixed in 4.81.0
  • Fix · GHSA-4f9r-x588-pp2h github.com/fleetdm/fleet/v4 (Go) Fixed in 4.81.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34389
  2. 2026-10-03 Alias added: GHSA-4f9r-x588-pp2h

References

Advisory 2

Other 1

  • 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-2026-20084 Fleet Windows MDM Azure AD JWT Authentication Bypass CVSS 4.0HIGH 8.2
See all 31 →

Sources

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