---
id: CVE-2026-69777
title: >-
  Heap-based buffer overflow in Windows DHCP Client allows an authorized
  attacker to elevate privileges over an adjacent network.
summary: >-
  Heap-based buffer overflow in Windows DHCP Client allows an authorized
  attacker to elevate privileges over an adjacent network.
severity: high
cvss: 8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
vendor: microsoft
product: windows_11_24h2
affected:
  - windows_11_24h2 < 10.0.26100.9445
  - windows_11_25h2 < 10.0.26200.9445
  - windows_11_26h1 < 10.0.28000.2954
patched:
  - windows_11_24h2 10.0.26100.9445
  - windows_11_25h2 10.0.26200.9445
  - windows_11_26h1 10.0.28000.2954
published: '2026-09-08'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T14:17:31.680'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-69777'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69777'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-11T13:36:06.093001Z'
epss: 0.00576
epssPercentile: 0.4515
ingestedAt: '2026-09-08T19:08:49.619Z'
---

## Overview

Heap-based buffer overflow in Windows DHCP Client allows an authorized attacker to elevate privileges over an adjacent network.

## Affected

- `windows_11_24h2 < 10.0.26100.9445`
- `windows_11_25h2 < 10.0.26200.9445`
- `windows_11_26h1 < 10.0.28000.2954`

## Remediation

Upgrade past the affected range:

- `windows_11_24h2 10.0.26100.9445`
- `windows_11_25h2 10.0.26200.9445`
- `windows_11_26h1 10.0.28000.2954`