---
id: "CVE-2026-121671"
page: "https://infrastack.ai/live/CVE-2026-121671"
kind: "vulnerability"
aliases: ["CVE-2026-121671"]
title: "Windows Audio Service: use-after-free lets a local user gain privileges"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Windows Audio Service", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "Windows 10 21H2", "fixed": ["10.0.19044.7846"], "affected": ">=10.0.19044.0, <10.0.19044.7846", "ecosystem": "vendor"}, {"name": "Windows 10 22H2", "fixed": ["10.0.19045.7846"], "affected": ">=10.0.19045.0, <10.0.19045.7846", "ecosystem": "vendor"}, {"name": "Windows 11 23H2", "fixed": ["10.0.22631.7711"], "affected": ">=10.0.22631.0, <10.0.22631.7711", "ecosystem": "vendor"}, {"name": "Windows 11 24H2", "fixed": ["10.0.26100.9974"], "affected": ">=10.0.26100.0, <10.0.26100.9974", "ecosystem": "vendor"}, {"name": "Windows 11 25H2", "fixed": ["10.0.26200.9974"], "affected": ">=10.0.26200.0, <10.0.26200.9974", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["infrastructure", "local-privilege-escalation", "windows", "windows-audio"]
not_affected_if: ["patched-build"]
published_at: "2026-11-10T19:20:30+00:00"
first_seen_at: "2026-11-10T19:25:09+00:00"
updated_at: "2026-11-10T21:45:13+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121671", "first_seen_at": "2026-11-10T19:25:09+00:00"}, {"source": "analyst", "url": "https://radar.offseq.com/threat/cve-2026-121671-cwe-416-use-after-free-in-microsoft-windows-10-version-21h2-c8ab12ba039ada5b", "first_seen_at": "2026-11-10T21:45:13+00:00", "cites": ["https://radar.offseq.com/threat/cve-2026-121671-cwe-416-use-after-free-in-microsoft-windows-10-version-21h2-c8ab12ba039ada5b"]}]
exploit_sources: []
---

# Windows Audio Service: use-after-free lets a local user gain privileges

Link for people: https://infrastack.ai/live/CVE-2026-121671 (this .md is for agents)

Use-after-free in the Windows Audio Service lets a user with a local account gain higher privileges (CVSS 7.0, local, high complexity). Microsoft's CVE record lists fixed builds for Windows 10 21H2/22H2 and Windows 11 23H2/24H2/25H2. No exploitation reported.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Windows Audio Service affected range not listed fixed no fixed version listed
- vendor:Windows 10 21H2 affected >=10.0.19044.0, <10.0.19044.7846 fixed 10.0.19044.7846
- vendor:Windows 10 22H2 affected >=10.0.19045.0, <10.0.19045.7846 fixed 10.0.19045.7846
- vendor:Windows 11 23H2 affected >=10.0.22631.0, <10.0.22631.7711 fixed 10.0.22631.7711
- vendor:Windows 11 24H2 affected >=10.0.26100.0, <10.0.26100.9974 fixed 10.0.26100.9974
- vendor:Windows 11 25H2 affected >=10.0.26200.0, <10.0.26200.9974 fixed 10.0.26200.9974

## How to check

Run winver or [Environment]::OSVersion in PowerShell and compare the build with the fixed builds: Win10 21H2 10.0.19044.7846, Win10 22H2 10.0.19045.7846, Win11 23H2 10.0.22631.7711, Win11 24H2 10.0.26100.9974, Win11 25H2 10.0.26200.9974. Lower is exposed. Confirm on the MSRC page.

## Fix

Install the November 2026 Windows cumulative update that reaches the build for your version (see how-to-check). Per the CVE record via OffSeq; confirm on MSRC.

## Timeline

- 2026-11-10T19:25:09+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121671
- 2026-11-10T21:45:13+00:00 analyst https://radar.offseq.com/threat/cve-2026-121671-cwe-416-use-after-free-in-microsoft-windows-10-version-21h2-c8ab12ba039ada5b — MSRC page is JS-only and unreadable here; versions come from OffSeq mirror of the Microsoft CNA CVE record (secondary), so nothing marked verified. No exploitation or PoC seen (not in KEV).

## Documents

- [describes] OffSeq: CVE-2026-121671 (mirrors CVE record) https://radar.offseq.com/threat/cve-2026-121671-cwe-416-use-after-free-in-microsoft-windows-10-version-21h2-c8ab12ba039ada5b

## From the sources

Use after free in Windows Audio Service allows an authorized attacker to elevate privileges locally.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_