---
id: "CVE-2026-119405"
page: "https://infrastack.ai/live/CVE-2026-119405"
kind: "vulnerability"
aliases: ["CVE-2026-119405"]
title: "Windows: Backup Engine use-after-free lets a local user gain higher privileges"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"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"}, {"name": "Windows 11 26H1", "fixed": ["10.0.28000.3501"], "affected": ">= 10.0.28000.0, < 10.0.28000.3501", "ecosystem": "vendor"}, {"name": "Windows 11 26H2", "fixed": ["10.0.26300.9974"], "affected": ">= 10.0.26300.0, < 10.0.26300.9974", "ecosystem": "vendor"}]
ecosystems: []
tags: ["infrastructure", "local-privilege-escalation", "windows"]
not_affected_if: ["patched-build"]
published_at: "2026-11-10T19:19:55+00:00"
first_seen_at: "2026-11-10T19:24:57+00:00"
updated_at: "2026-11-10T22:52:03+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119405", "first_seen_at": "2026-11-10T19:24:57+00:00"}, {"source": "analyst", "url": "https://cveawg.mitre.org/api/cve/CVE-2026-119405", "first_seen_at": "2026-11-10T22:52:03+00:00", "cites": ["https://cveawg.mitre.org/api/cve/CVE-2026-119405", "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119405"]}]
exploit_sources: []
---

# Windows: Backup Engine use-after-free lets a local user gain higher privileges

Link for people: https://infrastack.ai/live/CVE-2026-119405 (this .md is for agents)

A use-after-free bug in the Windows Backup Engine lets an attacker who already has a local account raise their privileges. The sources say nothing about a remote trigger.

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

## Affected

- 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
- vendor:Windows 11 26H1 affected >= 10.0.28000.0, < 10.0.28000.3501 fixed 10.0.28000.3501
- vendor:Windows 11 26H2 affected >= 10.0.26300.0, < 10.0.26300.9974 fixed 10.0.26300.9974

## How to check

Run 'winver' or PowerShell '[System.Environment]::OSVersion.Version' and compare the full build (e.g. 10.0.26100.xxxx) with the fixed build for your Windows version; lower means exposed. Server editions are not listed in the CVE record; check the MSRC page for them.

## Fix

Install the November 2026 Windows cumulative update that brings the OS build to at least: 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, Win11 26H1 10.0.28000.3501, Win11 26H2 10.0.26300.9974. KB numbers are on the MSRC page, not read.

## Timeline

- 2026-11-10T19:24:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119405
- 2026-11-10T22:52:03+00:00 analyst https://cveawg.mitre.org/api/cve/CVE-2026-119405 — Read Microsoft's CNA CVE record (cveawg.mitre.org): affected builds and fixed builds per Windows version; CISA SSVC exploitation none; no PoC indexed. MSRC page is JS-only so not read directly; no mitigations or workarounds in sources.

## Documents

- [advisory] CVE-2026-119405 CVE record published by Microsoft (CNA): Windows Backup Engine Elevation of Privilege Vulnerability https://cveawg.mitre.org/api/cve/CVE-2026-119405
- [fix] MSRC Security Update Guide: CVE-2026-119405 (page is JavaScript-only, not readable by fetch) https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-119405

## From the sources

Use after free in Windows Backup Engine allows an authorized attacker to elevate privileges locally.

---

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