CVE-2026-23518
moderate-risk
Published 2026-01-21
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.
Do I need to act?
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0.05% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10
Critical
NETWORK
/ LOW complexity
Affected Vendors
References (2)
39
/ 100
moderate-risk
Severity
32/34 · Critical
Exploitability
0/34 · Minimal
Exposure
7/34 · Low