CVE-2026-23518

Status: AnalyzedCritical (9.3)—

Fleet is open source device management software. In versions prior to 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, a vulnerability in Fleet's Windows MDM enrollment flow could allow an attacker to submit forged authentication tokens that are not properly validated. Because JWT signatures were not verified, Fleet could accept attacker-controlled identity claims, enabling enrollment of unauthorized devices under arbitrary Azure AD user identities. Versions 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3 fix the issue. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM.

CVSS

Version: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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
Base score: 9.3

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.26%
Percentile among all scored CVEs: 16
Score date: 10/5/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access90 %
Primary impactT1078 Valid Accountsstealth · persistence · privilege escalation · initial access85 %
Secondary impactT1098 Account Manipulationpersistence · privilege escalation80 %

Vulnerabilidad en validación de JWT en flujo MDM remoto (AV:N, PR:N, UI:N): explotación T1190. Impactos: suplantación de identidades Azure AD (T1078) e inscripción de dispositivos no autorizados (T1098).

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management User Account Management Network Segmentation Multi-factor Authentication Application Developer Guidance Active Directory Configuration

Affected technologies (1)

Fleetdm — Fleet

CWEs

CWE-347

References

Raw JSON (NVD)

Show

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