CVE-2026-22808
Cross-Site Scripting in Fleet MDM Enables Admin Token Theft
Publication date: 2026-01-21
Last updated on: 2026-02-18
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| fleetdm | fleet | to 4.53.3 (exc) |
| fleetdm | fleet | From 4.75.0 (inc) to 4.75.2 (exc) |
| fleetdm | fleet | From 4.76.0 (inc) to 4.76.2 (exc) |
| fleetdm | fleet | From 4.78.0 (inc) to 4.78.2 (exc) |
| fleetdm | fleet | 4.77.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a cross-site scripting (XSS) issue in fleetdm/fleet device management software when Windows MDM is enabled. An unauthenticated attacker can exploit this XSS flaw to steal a Fleet administrator's authentication token (FLEET::auth_token) from localStorage, potentially gaining unauthorized administrative access to the Fleet system.
How can this vulnerability impact me? :
If exploited, this vulnerability can allow an attacker to gain unauthorized access to the Fleet system with administrative privileges. This includes the ability to view device data and modify configuration settings, which could compromise the security and management of devices under Fleet's control.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability immediately, upgrade Fleet to versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, or 4.53.3 where the issue is fixed. If an immediate upgrade is not possible, temporarily disable Windows MDM.