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CVE-2026-23998— Fleet has a Windows MDM management endpoint authentication bypass

Quick assessment

Affected
fleetdm fleet
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Fleet是Fleet Device Management开源的一个设备管理平台，支持多种操作系统和设备，帮助 IT 和安全团队进行设备管理、漏洞报告、MDM 等操作。 Fleet 4.81.0之前版本存在信任管理问题漏洞，该漏洞源于Windows MDM管理端点未正确验证客户端证书，可能导致攻击者冒充已注册的Windows设备并检索敏感配置数据。

AI Predicted 5.3 Difficulty: Moderate EPSS 0.21% · P11

Affected Version Matrix 1

VendorProduct Version RangeStatus
fleetdm fleet < 4.81.0 affected
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I. Basic Information for CVE-2026-23998

Vulnerability Information
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Vulnerability Title
Fleet has a Windows MDM management endpoint authentication bypass
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
证书验证不恰当
Source: CVE Program / CVE List V5
Vulnerability Title
Fleet 信任管理问题漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Fleet是Fleet Device Management开源的一个设备管理平台，支持多种操作系统和设备，帮助 IT 和安全团队进行设备管理、漏洞报告、MDM 等操作。 Fleet 4.81.0之前版本存在信任管理问题漏洞，该漏洞源于Windows MDM管理端点未正确验证客户端证书，可能导致攻击者冒充已注册的Windows设备并检索敏感配置数据。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
fleetdm fleet < 4.81.0 -

II. Public POCs for CVE-2026-23998

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III. Intelligence Information for CVE-2026-23998

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Vendor Advisories for CVE-2026-23998 (1)

Other References for CVE-2026-23998 (1)

Same Patch Batch · fleetdm · 2026-05-14 · 6 CVEs total

CVE-2026-26062 Fleet server may terminate unexpectedly when handling certain gRPC requests
CVE-2026-26191 Fleet vulnerable to OS command injection in software packages
CVE-2026-24000 Fleet has a rate limiting bypass via untrusted client IP headers
CVE-2026-24899 Fleet Windows MDM Azure AD JWT Authentication Bypass
CVE-2026-46356 Fleet: IP spoofing allows bypassing API rate limiting

IV. Related Vulnerabilities

Same product: fleet
Same vendor: fleetdm
Same weakness: CWE-295

V. Comments for CVE-2026-23998

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