---
id: CVE-2026-83511
title: >-
  Weak authentication in Active Directory Federation Services (AD FS) allows an
  unauthorized attacker to perform spoofing over a network.
summary: >-
  Weak authentication in Active Directory Federation Services (AD FS) allows an
  unauthorized attacker to perform spoofing over a network.
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-1390
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T19:29:52.750'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-83511'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83511'
    label: secure@microsoft.com
tags:
  - nvd
ingestedAt: '2026-10-13T19:43:29.061Z'
---

## Overview

Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to perform spoofing over a network.

## Remediation

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