CVE-2026-34388
Fleet vulnerable to Denial of Service via unhandled gRPC log type in launcher endpoint
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.
INFO
Published Date :
March 27, 2026, 8:16 p.m.
Last Modified :
April 2, 2026, 7:34 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Fleet to version 4.81.0 or later.
- Apply the vendor-released patch.
- Restart the Fleet server process.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-34388.
| URL | Resource |
|---|---|
| https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-34388 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-34388
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-34388 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-34388 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 02, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* versions up to (excluding) 4.81.0 Added Reference Type GitHub, Inc.: https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv Types: Vendor Advisory -
New CVE Received by [email protected]
Mar. 27, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-703 Added Reference https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv