What’s Vulnerable › Vulnerabilities
CVE-2026-22808: Fleet Windows MDM endpoint has a Cross-site Scripting vulnerability
- Severity: medium (CVSS 5.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-01-21 · updated 2026-06-17
- Weakness: CWE-79
Description
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; from 4.75.0 before 4.75.2; from 4.76.0 before 4.76.2; from 4.78.0 before 4.78.2; 4.77.0 — fixed in 4.53.3, 4.75.2, 4.76.2, 4.78.2
How to fix
Upgrade to a fixed version: fleetdm fleet 4.53.3, 4.75.2, 4.76.2, 4.78.2. Check the vendor advisory for mitigations.
References
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