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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| fleetdm | fleet | >= 4.78.0, < 4.78.2, >= 4.77.0, < 4.77.1, >= 4.76.0, < 4.76.2, < 4.53.3 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260205T172317-150000.1.146.1 | SUSE-SU-2026:0403-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/fleetdm/fleet | >= 4.78.0, < 4.78.2 | 4.78.2 | GHSA-gfpw-jgvr-cw4j |
| Go | github.com/fleetdm/fleet | >= 4.77.0, < 4.77.1 | 4.77.1 | GHSA-gfpw-jgvr-cw4j |
| Go | github.com/fleetdm/fleet | >= 4.76.0, < 4.76.2 | 4.76.2 | GHSA-gfpw-jgvr-cw4j |
| Go | github.com/fleetdm/fleet | >= 4.75.0, < 4.75.2 | 4.75.2 | GHSA-gfpw-jgvr-cw4j |
| Go | github.com/fleetdm/fleet/v4 | < 4.43.5-0.20260111020427-0e6c790803d1 | 4.43.5-0.20260111020427-0e6c790803d1 | GHSA-gfpw-jgvr-cw4j |
| Go | github.com/fleetdm/fleet/v4 | >= 4.75.0, < 4.75.2 · >= 4.76.0, < 4.76.2 · >= 4.77.0, < 4.77.1 · >= 4.78.0, < 4.78.2 | 4.75.2, 4.76.2, 4.77.1, 4.78.2 | GO-2026-4336 |
Advisories 2
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- SUSE-SU-2026:0403-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Mar 23, 2026