CVE-2026-34391Network attack vector

Cross-device command disclosure via unscoped SyncML lookup

Published Mar 27, 2026 · Updated Mar 27, 2026

Information disclosure in Fleet before 4.81.1 allows remote attackers to read other devices' Windows MDM commands through an enrolled device. A device-controlled value in a SyncML status response is used to search a shared command table without validation or device scoping, and matching commands are re-queued to the attacker's device. Windows MDM must be enabled and the malicious device enrolled; exposed commands can contain WiFi credentials, VPN secrets, and certificates, but the control plane is not compromised.

CVSS severity7.5
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Fleet before 4.81.1 allows remote attackers to read other devices' Windows MDM commands through an enrolled device. A device-controlled value in a SyncML status response is used to search a shared command table without validation or device scoping, and matching commands are re-queued to the attacker's device. Windows MDM must be enabled and the malicious device enrolled; exposed commands can contain WiFi credentials, VPN secrets, and certificates, but the control plane is not compromised.

The record

CVE
CVE-2026-34391
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Fleet Device Management
Product
Fleet
Classifications
CWE-488, CAPEC-59, CAPEC-60, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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=< 4.81.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fleet Device Management · Fleetversion=< 4.81.1

Published CVSS scores

6.6GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-488Exposure of Data Element to Wrong Session
CAPEC-59Session Credential Falsification through Prediction
CAPEC-60Reusing Session IDs (aka Session Replay)
T1190Exploit Public-Facing Application

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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