Vulnerability · Published Oct 13, 2026 · Assigned by microsoft
CVE-2026-83674Active Directory Federation Services (AD FS) Spoofing Vulnerability
High 8.1
In plain English
A high-severity security flaw in Windows 10 Version 1607 from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).
Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.7%top 46.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 Version 1607 | 10.0.14393.0 – before 10.0.14393.9612 |
| Microsoft | Windows 10 Version 1809 | 10.0.17763.0 – before 10.0.17763.9376 |
| Microsoft | Windows Server 2016 | 10.0.14393.0 – before 10.0.14393.9612 |
| Microsoft | Windows Server 2016 (Server Core installation) | 10.0.14393.0 – before 10.0.14393.9612 |
| Microsoft | Windows Server 2019 | 10.0.17763.0 – before 10.0.17763.9376 |
| Microsoft | Windows Server 2019 (Server Core installation) | 10.0.17763.0 – before 10.0.17763.9376 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – before 10.0.20348.5761 |
| Microsoft | Windows Server 2025 | 10.0.26100.0 – before 10.0.26100.33650 |
| Microsoft | Windows Server 2025 (Server Core installation) | 10.0.26100.0 – before 10.0.26100.33650 |
Weakness: CWE-1390 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References
- Active Directory Federation Services (AD FS) Spoofing Vulnerability vendor-advisory, patch