CVSS 4.0
9.3 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NCVE-2026-23518
Critical (9.3) in fleetdm fleet. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in github.com/fleetdm/fleet 4.43.5-0.20260112202845-e225ef57912c, 4.75.2, 4.76.2.
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.
Severity
CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 17% of CVEs (scores of 2026-10-31)
- CWE
- CWE-347
- Published
- Modified
- Record from
- the NVD, synced
Affected
- fleetdm:fleet
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-63m5-974w-448v | Go | github.com/fleetdm/fleet | >=4.78.0 <4.78.3 | 4.78.3 |
| GHSA-63m5-974w-448v | Go | github.com/fleetdm/fleet | >=4.77.0 <4.77.1 | 4.77.1 |
| GHSA-63m5-974w-448v | Go | github.com/fleetdm/fleet | >=4.76.0 <4.76.2 | 4.76.2 |
| GHSA-63m5-974w-448v | Go | github.com/fleetdm/fleet | >=4.75.0 <4.75.2 | 4.75.2 |
| GHSA-63m5-974w-448v | Go | github.com/fleetdm/fleet | <4.43.5-0.20260112202845-e225ef57912c | 4.43.5-0.20260112202845-e225ef57912c |
| GO-2026-4335 | 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 <4.78.3 | 4.75.2, 4.76.2, 4.77.1, 4.78.3 |