CVE-2026-26062Network attack vector

Authenticated server crash via malformed PublishLogs request

Published May 14, 2026 · Updated May 14, 2026

Improper input validation in Fleet before 4.81.0 allows remote authenticated users to crash the server through a gRPC PublishLogs request. The PublishLogs handler fails to reject certain unexpected values before processing them; the vendor has not identified the values or failing operation. Access to any enrolled Launcher node key is sufficient, and one request terminates the Fleet process with availability-only impact.

CVSS severity8.7
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Fleet before 4.81.0 allows remote authenticated users to crash the server through a gRPC PublishLogs request. The PublishLogs handler fails to reject certain unexpected values before processing them; the vendor has not identified the values or failing operation. Access to any enrolled Launcher node key is sufficient, and one request terminates the Fleet process with availability-only impact.

The record

CVE
CVE-2026-26062
Published
May 14, 2026
Updated
May 14, 2026
Vendor
Fleet Device Management
Product
Fleet
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 14, 2026CVE publishedPublication date reported by the CVE source.
  2. May 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.81.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fleet Device Management · Fleetversion=< 4.81.0

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.7GitHub, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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