Vulnerability · Published Oct 13, 2026 · Assigned by microsoft
CVE-2026-83646Active Directory Federation Services (AD FS) Spoofing Vulnerability
Medium 4.8
In plain English
A medium-severity open redirect 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 0.4% (higher than 32% of all known vulnerabilities).
Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.4%top 68.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Url redirection to untrusted site ('open redirect') in Active Directory Federation Services (AD FS) allows an authorized 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-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C
References
- Active Directory Federation Services (AD FS) Spoofing Vulnerability vendor-advisory, patch