---
id: CVE-2026-62815
title: Microsoft QUIC Remote Code Execution Vulnerability
summary: >-
  Use after free in Microsoft QUIC allows an unauthorized attacker to execute
  code over a network.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-416
vendor: Microsoft
product: Windows 11 version 23H2
affected:
  - windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7517
  - windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7517
  - windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9168
  - windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9168
  - windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2704
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5499
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33296
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.33296
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-08-10T00:00:00+00:00'
published: '2026-08-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T13:44:50.796Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-62815'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62815'
    label: Microsoft QUIC Remote Code Execution Vulnerability
  - url: >-
      https://github.com/microsoft/msquic/security/advisories/GHSA-92f5-vc22-8j33
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-62815'
  - url: 'https://github.com/microsoft/msquic/pull/6217'
  - url: 'https://github.com/microsoft/msquic/pull/6219'
  - url: 'https://github.com/microsoft/msquic/pull/6220'
  - url: >-
      https://github.com/microsoft/msquic/commit/583e7d5b509bb0bfa3518482d98879b6eda41ad0
  - url: >-
      https://github.com/microsoft/msquic/commit/9ff06b71fd4b4d5258361598ada5b24cbc1beb20
  - url: >-
      https://github.com/microsoft/msquic/commit/e0f55b5fdc9fff0b4465976d066ebd22fb7e2b3b
  - url: 'https://github.com/microsoft/msquic/releases/tag/v2.4.19'
  - url: 'https://github.com/microsoft/msquic/releases/tag/v2.5.10'
  - url: 'https://github.com/advisories/GHSA-92f5-vc22-8j33'
tags:
  - cve.org
  - ghsa
  - nuget
epss: 0.01238
epssPercentile: 0.67799
aliases:
  - GHSA-92f5-vc22-8j33
ecosystem: nuget
patched:
  - Microsoft.Native.Quic.MsQuic.OpenSSL 2.5.10
  - Microsoft.Native.Quic.MsQuic.Schannel 2.5.10
  - Microsoft.Native.Quic.MsQuic.OpenSSL 2.4.19
  - Microsoft.Native.Quic.MsQuic.Schannel 2.4.19
ingestedAt: '2026-09-08T18:07:34.898Z'
---

## Overview

Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.

## Affected

- `windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7517`
- `windows_11_version_23h2 >= 10.0.22631.0 < 10.0.22631.7517`
- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9168`
- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9168`
- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2704`
- `windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5499`
- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33296`
- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33296`

## Remediation

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

## Package advisory (CVE-2026-62815)

Affected packages:

- `Microsoft.Native.Quic.MsQuic.OpenSSL >= 2.5.3, < 2.5.10`
- `Microsoft.Native.Quic.MsQuic.Schannel >= 2.5.3, < 2.5.10`
- `Microsoft.Native.Quic.MsQuic.OpenSSL < 2.4.19`
- `Microsoft.Native.Quic.MsQuic.Schannel < 2.4.19`

Patched in:

- `Microsoft.Native.Quic.MsQuic.OpenSSL 2.5.10`
- `Microsoft.Native.Quic.MsQuic.Schannel 2.5.10`
- `Microsoft.Native.Quic.MsQuic.OpenSSL 2.4.19`
- `Microsoft.Native.Quic.MsQuic.Schannel 2.4.19`

Source: https://github.com/advisories/GHSA-92f5-vc22-8j33