CVE-2026-22808: Fleetdm Fleet

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

fleetdm/fleet is open source device management software. Prior to versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, if Windows MDM is enabled, an unauthenticated attacker can exploit this XSS vulnerability to steal a Fleet administrator's authentication token (FLEET::auth_token) from localStorage. This could allow unauthorized access to Fleet, including administrative access, visibility into device data, and modification of configuration. Versions 4.78.2, 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.

Affected products

• Fleetdm Fleet: before 4.53.3 (fixed in 4.53.3); from 4.75.0, before 4.75.2 (fixed in 4.75.2); from 4.76.0, before 4.76.2 (fixed in 4.76.2); from 4.78.0, before 4.78.2 (fixed in 4.78.2); version 4.77.0 only

Published 2026-01-21. Last modified 2026-06-17.