Fleet is open source device management software. Prior to version 4.81.0, a vulnerability in Fleet’s Windows MDM management endpoint could allow requests to be processed without proper client certificate validation. In certain circumstances, this could allow an attacker to impersonate an enrolled Windows device and retrieve sensitive configuration data. Fleet’s Windows MDM management endpoint relies on mutual TLS (mTLS) client certificates to authenticate enrolled devices. In affected versions, requests that did not present a client certificate could be incorrectly treated as trusted. As a result, an attacker with prior knowledge of a valid enrolled device identifier could potentially impersonate that device and receive configuration payloads intended for it. These payloads may contain sensitive information such as Wi-Fi or VPN configuration data, certificates, or other secrets delivered through MDM profiles. This issue does not allow enrollment of new devices, administrative access to Fleet, or compromise of the Fleet control plane. Impact is limited to the targeted Windows device. Version 4.81.0 contains a patch. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-2rc4-7jc6-qffh | Fleet has a Windows MDM management endpoint authentication bypass |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 14 May 2026 20:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Fleetdm
Fleetdm fleet |
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| Vendors & Products |
Fleetdm
Fleetdm fleet |
Thu, 14 May 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Fleet is open source device management software. Prior to version 4.81.0, a vulnerability in Fleet’s Windows MDM management endpoint could allow requests to be processed without proper client certificate validation. In certain circumstances, this could allow an attacker to impersonate an enrolled Windows device and retrieve sensitive configuration data. Fleet’s Windows MDM management endpoint relies on mutual TLS (mTLS) client certificates to authenticate enrolled devices. In affected versions, requests that did not present a client certificate could be incorrectly treated as trusted. As a result, an attacker with prior knowledge of a valid enrolled device identifier could potentially impersonate that device and receive configuration payloads intended for it. These payloads may contain sensitive information such as Wi-Fi or VPN configuration data, certificates, or other secrets delivered through MDM profiles. This issue does not allow enrollment of new devices, administrative access to Fleet, or compromise of the Fleet control plane. Impact is limited to the targeted Windows device. Version 4.81.0 contains a patch. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM. | |
| Title | Fleet has a Windows MDM management endpoint authentication bypass | |
| Weaknesses | CWE-295 | |
| References |
| |
| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-14T18:48:38.765Z
Reserved: 2026-01-19T18:49:20.658Z
Link: CVE-2026-23998
No data.
Status : Received
Published: 2026-05-14T19:16:30.983
Modified: 2026-05-14T19:16:30.983
Link: CVE-2026-23998
No data.
OpenCVE Enrichment
Updated: 2026-05-14T20:30:04Z
Weaknesses
Github GHSA