High severity · published Mar 27, 2026
CVE-2026-34388
Fleet vulnerable to Denial of Service via unhandled gRPC log type in launcher endpoint
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FL
fleet · fleetdm
< 4.81.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34388
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34388
Vendor Advisory
https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv
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