---
id: CVE-2026-97788
title: >-
  Observable discrepancy in Active Directory Federation Services (AD FS) allows
  an unauthorized attacker to disclose information over a network.
summary: >-
  Observable discrepancy in Active Directory Federation Services (AD FS) allows
  an unauthorized attacker to disclose information over a network.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-203
vendor: microsoft
product: .net_framework
affected:
  - windows_10_1607 < 10.0.14393.9612
  - windows_10_1809 < 10.0.17763.9376
  - windows_10_21h2 < 10.0.19044.7807
  - windows_10_22h2 < 10.0.19045.7807
  - windows_11_23h2 < 10.0.22631.7652
  - windows_11_24h2 < 10.0.26100.9711
  - windows_11_25h2 < 10.0.26200.9711
  - windows_11_26h1 < 10.0.28000.3231
  - windows_11_26h2 < 10.0.26300.9711
  - windows_server_2012
  - windows_server_2012 = r2
  - windows_server_2016 < 10.0.14393.9612
  - windows_server_2019 < 10.0.17763.9376
  - windows_server_2022 < 10.0.20348.5761
  - windows_server_2025 < 10.0.26100.33650
  - .net_framework = 4.8.1
  - .net_framework = 4.8
  - .net_framework = 4.6.2
  - .net_framework = 4.7
  - .net_framework = 4.7.1
  - .net_framework = 4.7.2
  - .net_framework = 3.5
patched:
  - windows_10_1607 10.0.14393.9612
  - windows_10_1809 10.0.17763.9376
  - windows_10_21h2 10.0.19044.7807
  - windows_10_22h2 10.0.19045.7807
  - windows_11_23h2 10.0.22631.7652
  - windows_11_24h2 10.0.26100.9711
  - windows_11_25h2 10.0.26200.9711
  - windows_11_26h1 10.0.28000.3231
  - windows_11_26h2 10.0.26300.9711
  - windows_server_2016 10.0.14393.9612
  - windows_server_2019 10.0.17763.9376
  - windows_server_2022 10.0.20348.5761
  - windows_server_2025 10.0.26100.33650
published: '2026-10-13'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:32:12.930'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97788'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97788'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00876
epssPercentile: 0.58816
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-13T19:31:42.754445Z'
ingestedAt: '2026-10-13T19:43:29.305Z'
---

## Overview

Observable discrepancy in Active Directory Federation Services (AD FS) allows an unauthorized attacker to disclose information over a network.

## Affected

- `windows_10_1607 < 10.0.14393.9612`
- `windows_10_1809 < 10.0.17763.9376`
- `windows_10_21h2 < 10.0.19044.7807`
- `windows_10_22h2 < 10.0.19045.7807`
- `windows_11_23h2 < 10.0.22631.7652`
- `windows_11_24h2 < 10.0.26100.9711`
- `windows_11_25h2 < 10.0.26200.9711`
- `windows_11_26h1 < 10.0.28000.3231`
- `windows_11_26h2 < 10.0.26300.9711`
- `windows_server_2012`
- `windows_server_2012 = r2`
- `windows_server_2016 < 10.0.14393.9612`
- `windows_server_2019 < 10.0.17763.9376`
- `windows_server_2022 < 10.0.20348.5761`
- `windows_server_2025 < 10.0.26100.33650`
- `.net_framework = 4.8.1`
- `.net_framework = 4.8`
- `.net_framework = 4.6.2`
- `.net_framework = 4.7`
- `.net_framework = 4.7.1`
- `.net_framework = 4.7.2`
- `.net_framework = 3.5`

## Remediation

Upgrade past the affected range:

- `windows_10_1607 10.0.14393.9612`
- `windows_10_1809 10.0.17763.9376`
- `windows_10_21h2 10.0.19044.7807`
- `windows_10_22h2 10.0.19045.7807`
- `windows_11_23h2 10.0.22631.7652`
- `windows_11_24h2 10.0.26100.9711`
- `windows_11_25h2 10.0.26200.9711`
- `windows_11_26h1 10.0.28000.3231`
- `windows_11_26h2 10.0.26300.9711`
- `windows_server_2016 10.0.14393.9612`
- `windows_server_2019 10.0.17763.9376`
- `windows_server_2022 10.0.20348.5761`
- `windows_server_2025 10.0.26100.33650`