---
id: CVE-2026-88099
title: >-
  Uncaught exception in Windows Failover Cluster allows an unauthorized attacker
  to deny service over a network.
summary: >-
  Uncaught exception in Windows Failover Cluster allows an unauthorized attacker
  to deny service over a network.
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-248
vendor: microsoft
product: windows_server_2019
affected:
  - windows_server_2019 < 10.0.17763.9376
  - windows_server_2022 < 10.0.20348.5761
  - windows_server_2025 < 10.0.26100.33650
patched:
  - 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: '2026-10-16T15:43:48.160'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88099'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00818
epssPercentile: 0.56968
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-13T19:58:10.343167Z'
ingestedAt: '2026-10-13T19:43:29.211Z'
---

## Overview

Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.

## Affected

- `windows_server_2019 < 10.0.17763.9376`
- `windows_server_2022 < 10.0.20348.5761`
- `windows_server_2025 < 10.0.26100.33650`

## Remediation

Upgrade past the affected range:

- `windows_server_2019 10.0.17763.9376`
- `windows_server_2022 10.0.20348.5761`
- `windows_server_2025 10.0.26100.33650`