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…
Exact source revision recorded 27 Oct 2026 06:23:38 UTC. It does not establish the source's current position. Latest evidence.
nvd · CVE-2026-23998
PublishedFleet 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.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-295
Original publisher date fields
published: 2026-05-14T19:16:30.983
lastModified: 2026-10-26T14:10:00.130
1 source CPE criteria · context only
- cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 14 May 2026 19:16:30 UTC
- Source modified
- 26 Oct 2026 14:10:00 UTC
- Observed here
- 27 Oct 2026 06:23:38 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 4.0 · [email protected] · Secondary · 8.2 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/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
CVSS 3.1 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N