CVE-2026-34388 PUBLISHED

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

Assigner: GitHub_M
Reserved: 27.03.2026 Published: 27.03.2026 Updated: 27.03.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
CVSS Score: 6.6

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

CVSS 4.0

Product Status

Vendor	fleetdm
Product	fleet
Versions	Version < 4.81.0 is affected

References

https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv

Problem Types

CWE-703: Improper Check or Handling of Exceptional Conditions CWE