VDB
CVE-2026-23518
CVE-2026-23518
PUBLISHED
CVSS 9.300000190734863 CRITICAL
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.
EPSS 0.23% · 14.6th percentile
Risk Scores
CVSS 4.0
9.300000190734863
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS Score
0.23%
14.6th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| fleetdm | fleet | 4.78.0, 0, >= 4.76.0, < 4.76.2 |
| github.com | fleetdm/fleet | 4.77.0, 4.76.0, 0 |
Timeline
- Jan 20, 2026 CVE Published
- Jan 21, 2026 PoC Published
- Jan 22, 2026 EPSS Score
- Jan 22, 2026 PoC Published
- Jan 22, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 25, 2026 EPSS Score
- Jan 28, 2026 EPSS Score
- Jan 30, 2026 Security Advisory
- Jan 31, 2026 EPSS Score
References
- https://github.com/fleetdm/fleet/commit/e225ef57912c8f4ac8977e24b5ebe1d9fd875257 patch
- https://github.com/fleetdm/fleet/security/advisories/GHSA-63m5-974w-448v advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-23518 advisory
- https://github.com/fleetdm/fleet package
- https://pkg.go.dev/vuln/GO-2026-4335 url