---
id: CVE-2026-83646
title: >-
  Url redirection to untrusted site ('open redirect') in Active Directory
  Federation Services (AD FS) allows an authorized attacker to perform spoofing
  over a network.
summary: >-
  Url redirection to untrusted site ('open redirect') in Active Directory
  Federation Services (AD FS) allows an authorized attacker to perform spoofing
  over a network.
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-601
vendor: Microsoft
product: Windows 10 Version 1607
affected:
  - windows_10_version_1607 >= 10.0.14393.0 < 10.0.14393.9612
  - windows_10_version_1809 >= 10.0.17763.0 < 10.0.17763.9376
  - windows_server_2016 >= 10.0.14393.0 < 10.0.14393.9612
  - >-
    windows_server_2016_server_core_installation >= 10.0.14393.0 <
    10.0.14393.9612
  - windows_server_2019 >= 10.0.17763.0 < 10.0.17763.9376
  - >-
    windows_server_2019_server_core_installation >= 10.0.17763.0 <
    10.0.17763.9376
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5761
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33650
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.33650
published: '2026-10-13'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T16:21:12.173'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-83646'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83646'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00417
epssPercentile: 0.35811
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-16T00:58:59.253735Z'
ingestedAt: '2026-10-13T19:43:29.074Z'
---

## Overview

Url redirection to untrusted site ('open redirect') in Active Directory Federation Services (AD FS) allows an authorized attacker to perform spoofing over a network.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.