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TI-2026-26674 Aliases CVE-2026-34388GHSA-w254-4hp5-7cvv

Fleet vulnerable to Denial of Service via unhandled gRPC log type in launcher endpoint

Priority LOW 29CWE-703Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

Fleet is open source device management software. Prior to 4.81.0, a denial-of-service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers. Version 4.81.0 patches the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00273 19th 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
No
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-w254-4hp5-7cvv
  • 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-w254-4hp5-7cvv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*before 4.81.0Vulnerablefleetdm
  • cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* Versions before 4.81.0 Vulnerable ·fleetdm

Remediation

  • Fix · CNA fleet (fleetdm) Fixed in 4.81.0
  • Fix · GHSA-w254-4hp5-7cvv github.com/fleetdm/fleet/v4 (Go) Fixed in 4.81.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34388
  2. 2026-10-03 Alias added: GHSA-w254-4hp5-7cvv

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